Which would hit the ground first if dropped from the same height in a vacuum—a feather or a metal bolt?
Answer: They would hit the ground at the same time
A baseball catcher throws a ball vertically upward and catches it in the same spot as it returns to the mitt. At what point in the ball's path does it experience zero velocity and nonzero acceleration at the same time?
A baseball catcher throws a ball vertically upward and catches it in the same spot as it returns to the mitt. At what point in the ball's path does it experience zero velocity and nonzero acceleration at the same time?
Answer: at the top of its path
Which of the following statements applies to the motion of a ball rising and then falling in free fall?
Which of the following statements applies to the motion of a ball rising and then falling in free fall?
I. The ball has constant acceleration as it moves upward.
II. The ball has constant acceleration at the top of its path.
III. The ball has constant acceleration as it moves downward.
Answer: I, II, and III
Acceleration due to gravity is also called
Acceleration due to gravity is also called
Answer: free-fall acceleration
When a car's velocity is negative and its acceleration is negative, what is happening to the car's motion?
When a car's velocity is negative and its acceleration is negative, what is happening to the car's motion?
Answer: The car speeds up
When a car's velocity is positive and its acceleration is negative, what is happening to the car's motion?
When a car's velocity is positive and its acceleration is negative, what is happening to the car's motion?
Answer: The car slows down
If you know the acceleration of a car, its initial velocity, and the time interval, which of the following can you predict?
If you know the acceleration of a car, its initial velocity, and the time interval, which of the following can you predict?
the direction of the car's final velocity
the magnitude of the car's final velocity
the displacement of the car
Suppose you are given a position versus time graph. The slope of a line drawn tangent to a point on the curve of this graph describes what quantity?
Suppose you are given a position versus time graph. The slope of a line drawn tangent to a point on the curve of this graph describes what quantity?
Answer: instantaneous velocity
Which of the following is the equation for average velocity?
Which of the following is the equation for average velocity?
Answer: avg v= (delta x)/(delta t)
The driver of a car traveling at 110 km/h slams on the brakes so that the car undergoes a constant acceleration, skidding to a complete stop in 4.5 s.
The driver of a car traveling at 110 km/h slams on the brakes so that the car undergoes a constant acceleration, skidding to a complete stop in 4.5 s.
Answer: -6.79 m/s^2
John goes for a run. From his house, he jogs north for exactly 5.0 min at an average speed of 8.0 km/h. He continues north at a speed of 12.0 km/h for the next 30.0 min. He then turns around and jogs south at a speed of 15.0 km/h for 15.0 min. Then he jogs south for another 20.0 min at 8.0 km/h. He walks the rest of the way home.
John goes for a run. From his house, he jogs north for exactly 5.0 min at an average speed of 8.0 km/h. He continues north at a speed of 12.0 km/h for the next 30.0 min. He then turns around and jogs south at a speed of 15.0 km/h for 15.0 min. Then he jogs south for another 20.0 min at 8.0 km/h. He walks the rest of the way home.
Answer: 0.25 km
John goes for a run. From his house, he jogs north for exactly 5.0 min at an average speed of 8.0 km/h. He continues north at a speed of 12.0 km/h for the next 30.0 min. He then turns around and jogs south at a speed of 15.0 km/h for 15.0 min. Then he jogs south for another 20.0 min at 8.0 km/h. He walks the rest of the way home.
John goes for a run. From his house, he jogs north for exactly 5.0 min at an average speed of 8.0 km/h. He continues north at a speed of 12.0 km/h for the next 30.0 min. He then turns around and jogs south at a speed of 15.0 km/h for 15.0 min. Then he jogs south for another 20.0 min at 8.0 km/h. He walks the rest of the way home.
Answer: 13.1 km
Moustapha Jones drives east at 100km/hr for 3 hours the back west at 80km/hr for 1.5 hours. Which pair of answers gives his average speed and average velocity?
Moustapha Jones drives east at 100km/hr for 3 hours the back west at 80km/hr for 1.5 hours. Which pair of answers gives his average speed and average velocity?
Answer: 93.3km/hr, 40km/hr east
In the graph above, a toy car rolls from +3 m to +5 m. Which of the following statements is true?
In the graph above, a toy car rolls from +3 m to +5 m. Which of the following statements is true?
Answer: xi = +3 m
In the graph above, what is the correct description of any location to the left of the zero?
In the graph above, what is the correct description of any location to the left of the zero?
Answer: negative position
Which of the following units is the SI unit of velocity?
Which of the following units is the SI unit of velocity?
Answer: meter per second
Which of the following situations represents a negative displacement? (Assume positive position is measured vertically upward along a y-axis.)
Which of the following situations represents a negative displacement? (Assume positive position is measured vertically upward along a y-axis.)
Answer: A cat jumps from a tree limb to the ground
What is the speed of an object at rest?
What is the speed of an object at rest?
Answer: 0.0 m/s
Which of the following is a pair of vector quantities?
Which of the following is a pair of vector quantities?
Answer: Velocity — Displacement
A car is moving with a uniform speed of 15.0 m/s along a straight path. What is the distance covered by the car in 12.0 minutes?
A car is moving with a uniform speed of 15.0 m/s along a straight path. What is the distance covered by the car in 12.0 minutes?
Answer: 1.08 ´ 10^1 km
A lightweight object and a very heavy object are sliding with equal speeds along a level frictionless surface. They both slide up the same frictionless hill. Which rises to a greater height?
A lightweight object and a very heavy object are sliding with equal speeds along a level frictionless surface. They both slide up the same frictionless hill. Which rises to a greater height?
Answer: They both slide to the same height.
Which of the following are not units of power?
Which of the following are not units of power?
Answer: J
The area under the curve, on a Force versus position (F vs. x) graph, represents
The area under the curve, on a Force versus position (F vs. x) graph, represents
Answer: work.
Of the following, which is not a unit of power?
Of the following, which is not a unit of power?
Answer: watt/second
What is the correct unit of power expressed in SI units?
What is the correct unit of power expressed in SI units?
Answer: kg m2/s3
Which of the following is a true statement about the conservation of energy?
Which of the following is a true statement about the conservation of energy?
Answer: Total energy is always conserved.
A roller coaster starts with a speed of 5.0 m/s at a point 45 m above the bottom of a dip (See Fig. 6-2). Neglect friction, what will be the speed of the roller coaster at the top of the next slope, which is 30 m above the bottom of the dip?
A roller coaster starts with a speed of 5.0 m/s at a point 45 m above the bottom of a dip (See Fig. 6-2). Neglect friction, what will be the speed of the roller coaster at the top of the next slope, which is 30 m above the bottom of the dip?
Answer: 18 m/s
A ball drops some distance and gains 30 J of kinetic energy. Do not ignore air resistance. How much gravitational potential energy did the ball lose?
A ball drops some distance and gains 30 J of kinetic energy. Do not ignore air resistance. How much gravitational potential energy did the ball lose?
Answer: more than 30 J
Which of the following is the rate at which energy is transferred?
Which of the following is the rate at which energy is transferred?
Answer: power
On a plot of Force versus position (F vs. x), what represents the work done by the force F?
On a plot of Force versus position (F vs. x), what represents the work done by the force F?
Answer: the area under the curve
How much power is required to lift a 2.0 kg mass at a speed of 2.0 m/s
How much power is required to lift a 2.0 kg mass at a speed of 2.0 m/s
Answer: 39 J
A 3.00 kg toy falls from a height of 1.00 m. What will the kinetic energy of the toy be just before the toy hits the ground? (Assume no air resistance and that g = 9.81 m/s.)
A 3.00 kg toy falls from a height of 1.00 m. What will the kinetic energy of the toy be just before the toy hits the ground? (Assume no air resistance and that g = 9.81 m/s.)
Answer: 29.4 J
The quantity Fd/t is
The quantity Fd/t is
Answer: the power supplied to the object by the force.
To accelerate your car at a constant acceleration, the car's engine must
To accelerate your car at a constant acceleration, the car's engine must
Answer: develop ever-increasing power.
What is the average power supplied by a 60.0 kg person running up a flight of stairs a vertical distance of 4.0 m in 4.2 s?
What is the average power supplied by a 60.0 kg person running up a flight of stairs a vertical distance of 4.0 m in 4.2 s?
Answer: 560 W
The kinetic friction force between a 60.0-kg object and a horizontal surface is 50.0 N. If the initial speed of the object is 25.0 m/s, what distance will it slide before coming to a stop?
The kinetic friction force between a 60.0-kg object and a horizontal surface is 50.0 N. If the initial speed of the object is 25.0 m/s, what distance will it slide before coming to a stop?
Answer: 375 m
An acorn falls from a tree. Compare its kinetic energy K, to its potential energy U.
An acorn falls from a tree. Compare its kinetic energy K, to its potential energy U.
Answer: K increases and U decreases
A ball falls from the top of a building, through the air (air friction is present), to the ground below. How does the kinetic energy (K) just before striking the ground compare to the potential energy (U) at the top of the building?
A ball falls from the top of a building, through the air (air friction is present), to the ground below. How does the kinetic energy (K) just before striking the ground compare to the potential energy (U) at the top of the building?
Answer: K is less than U.
Consider two masses m1 and m2 at the top of two frictionless inclined planes. Both masses start from rest at the same height. However, the plane on which m1 sits is at an angle of 30° with the horizontal, while the plane on which m2 sits is at 60°. If the masses are released, which is going faster at the bottom of its plane?
Consider two masses m1 and m2 at the top of two frictionless inclined planes. Both masses start from rest at the same height. However, the plane on which m1 sits is at an angle of 30° with the horizontal, while the plane on which m2 sits is at 60°. If the masses are released, which is going faster at the bottom of its plane?
Answer: They both are going the same speed.
When a cannon fires a cannonball, the cannon will recoil backward because the
When a cannon fires a cannonball, the cannon will recoil backward because the
Answer: momentum of the cannonball and cannon is conserved.
A force is applied as shown in the graph. What impulse is given by this force?
A force is applied as shown in the graph. What impulse is given by this force?
Answer: 25 N m
The law of conservation of momentum states that
The law of conservation of momentum states that
Answer: the total momentum of all objects interacting with one another remains constant regardless of the nature of the forces between the objects.
When a light beach ball rolling with a speed of 6.0 m/s collides with a heavy exercise ball at rest, the beach ball's speed after the collision will be, approximately,
When a light beach ball rolling with a speed of 6.0 m/s collides with a heavy exercise ball at rest, the beach ball's speed after the collision will be, approximately,
Answer: 6.0 m/s.
Which of the following equations can be used to directly calculate the change in an object's momentum?
Which of the following equations can be used to directly calculate the change in an object's momentum?
Answer: Dp = FΔt
Which of the following statements properly relates the variables in the equation FΔt = Δp?
Which of the following statements properly relates the variables in the equation FΔt = Δp?
Answer: A large constant force acting over a long time interval causes a large change in momentum.
A roller coaster climbs up a hill at 4 m/s and then zips down the hill at 30 m/s. The momentum of the roller coaster
A roller coaster climbs up a hill at 4 m/s and then zips down the hill at 30 m/s. The momentum of the roller coaster
Answer: is greater down the hill than up the hill.
A child with a mass of 23 kg rides a bike with a mass of 5.5 kg at a velocity of 4.5 m/s to the south. Compare the momentum of the child with the momentum of the bike.
A child with a mass of 23 kg rides a bike with a mass of 5.5 kg at a velocity of 4.5 m/s to the south. Compare the momentum of the child with the momentum of the bike.
Answer: The child has a greater momentum than the bike.
A 100-kg football linebacker moving at 2.0 m/s tackles head-on an 80-kg halfback running 3.0 m/s. Neglecting the effects due to digging in of cleats,
A 100-kg football linebacker moving at 2.0 m/s tackles head-on an 80-kg halfback running 3.0 m/s. Neglecting the effects due to digging in of cleats,
Answer: the halfback will drive the linebacker backward.
Which of the following statements about the conservation of momentum is not correct?
Which of the following statements about the conservation of momentum is not correct?
Answer: Momentum is not conserved for a system of objects in a head-on collision.
Which of the following situations is an example of a significant change in momentum?
Which of the following situations is an example of a significant change in momentum?
Answer: A tennis ball is hit into a net.
A Ping-Pong ball moving east at a speed of 4 m/s, collides with a stationary bowling ball. The Ping-Pong ball bounces back to the west, and the bowling ball moves very slowly to the east. Which object experiences the greater magnitude impulse during the collision?
A Ping-Pong ball moving east at a speed of 4 m/s, collides with a stationary bowling ball. The Ping-Pong ball bounces back to the west, and the bowling ball moves very slowly to the east. Which object experiences the greater magnitude impulse during the collision?
Answer: Neither; both experienced the same magnitude impulse.
A cart of mass 5.3 kg initially moving at 5 m/s is subject to an impulse which can be found from the graph. What is the final speed of the car if the force acts in the direction of the intial velocity.
A cart of mass 5.3 kg initially moving at 5 m/s is subject to an impulse which can be found from the graph. What is the final speed of the car if the force acts in the direction of the intial velocity.
Answer: 11.0 m/s
Two skaters stand facing each other. One skater's mass is 60 kg, and the other's mass is 72 kg. If the skaters push away from each other without spinning,
Two skaters stand facing each other. One skater's mass is 60 kg, and the other's mass is 72 kg. If the skaters push away from each other without spinning,
Answer: their momenta are equal but opposite.
The change in an object's momentum is equal to
The change in an object's momentum is equal to
Answer: the product of the force applied to the object and the time interval.
A rubber ball moving at a speed of 5 m/s hit a flat wall and returned to the thrower at 5 m/s. The magnitude of the momentum of the rubber ball
A rubber ball moving at a speed of 5 m/s hit a flat wall and returned to the thrower at 5 m/s. The magnitude of the momentum of the rubber ball
Answer: remained the same.
What are the SI units for momentum?
What are the SI units for momentum?
Answer: kg m/s
A 2-kilogram piece of clay moving at 4 m/sec strikes and sticks to a second 4-kilogram piece of clay moving at 1 m/sec in the opposite direction. Calculate the speed of the combined piece of clay.
A 2-kilogram piece of clay moving at 4 m/sec strikes and sticks to a second 4-kilogram piece of clay moving at 1 m/sec in the opposite direction. Calculate the speed of the combined piece of clay.
Answer: 0.7 m/sec
Which of the following situations is an example of a visible change in momentum?
Which of the following situations is an example of a visible change in momentum?
Answer: A baseball is hit by a bat.
A 3.0-kg object moves to the right at 4.0 m/s. It collides head-on with a 6.0-kg object moving to the left at 2.0 m/s. Which statement is correct?
A 3.0-kg object moves to the right at 4.0 m/s. It collides head-on with a 6.0-kg object moving to the left at 2.0 m/s. Which statement is correct?
Answer: The total momentum both before and after the collision is zero.
A rubber ball and a lump of putty have equal mass. They are thrown with equal speed against a wall. The ball bounces back with nearly the same speed with which it hit. The putty sticks to the wall. Which objects experiences the greater momentum change?
A rubber ball and a lump of putty have equal mass. They are thrown with equal speed against a wall. The ball bounces back with nearly the same speed with which it hit. The putty sticks to the wall. Which objects experiences the greater momentum change?
Answer: the ball
A ball with a momentum of 4.0 kg m/s hits a wall and bounces straight back without losing any kinetic energy. What is the change in the ball's momentum?
A ball with a momentum of 4.0 kg m/s hits a wall and bounces straight back without losing any kinetic energy. What is the change in the ball's momentum?
Answer: -8.0 kg m/s
Which of the following has the greatest momentum?
Which of the following has the greatest momentum?
Answer: a tortoise with a mass of 275 kg moving at a velocity of 0.55 m/s
Which of the following is an accurate statement?
Which of the following is an accurate statement?
Answer: If an object is acted on by a non-zero net external force, its momentum will not remain constant
Two equal mass balls (one red and the other blue) are dropped from the same height, and rebound off the floor. The red ball rebounds to a higher position. Which ball is subjected to the greater magnitude of impulse during its collision with the floor?
Two equal mass balls (one red and the other blue) are dropped from the same height, and rebound off the floor. The red ball rebounds to a higher position. Which ball is subjected to the greater magnitude of impulse during its collision with the floor?
Answer: the red ball
Which of the following equations can be used to directly calculate an object's momentum, p?
Which of the following equations can be used to directly calculate an object's momentum, p?
Answer: p = mv
The impulse experienced by a body is equivalent to the body's change in
The impulse experienced by a body is equivalent to the body's change in
Answer: momentum
When comparing the momentum of two moving objects, which of the following is correct?
When comparing the momentum of two moving objects, which of the following is correct?
Answer: The less massive object will have less momentum if the velocities are the same.
A small car meshes with a large truck in a head-on collision. Which of the following statements concerning the magnitude of the average collision force is correct?
A small car meshes with a large truck in a head-on collision. Which of the following statements concerning the magnitude of the average collision force is correct?
Answer: The small car and the truck experience the same average force.
If you pitch a baseball with twice the kinetic energy you gave it in the previous pitch, the magnitude of its momentum is
If you pitch a baseball with twice the kinetic energy you gave it in the previous pitch, the magnitude of its momentum is
Answer: 1.41 times as much.
If a force is exerted on an object, which statement is true?
If a force is exerted on an object, which statement is true?
Answer: A small force applied over a long time interval can produce a large change in the object's momentum.
A person sitting in a chair with wheels stands up, causing the chair to roll backward across the floor. The momentum of the chair
A person sitting in a chair with wheels stands up, causing the chair to roll backward across the floor. The momentum of the chair
Answer: was zero while stationary and increased when the person stood.
A freight car moves along a frictionless level railroad track at constant speed. The car is open on top. A large load of coal is suddenly dumped into the car. What happens to the velocity of the car?
A freight car moves along a frictionless level railroad track at constant speed. The car is open on top. A large load of coal is suddenly dumped into the car. What happens to the velocity of the car?
Answer: It decreases.
A sailboat of mass m is moving with a momentum p. How would you represent its kinetic energy in terms of these two quantities?
A sailboat of mass m is moving with a momentum p. How would you represent its kinetic energy in terms of these two quantities?
Answer: p2/(2m)
A 20 kg shopping cart moving at a velocity of 0.5 m/s collides with a store wall and stops. The momentum of the shopping cart
A 20 kg shopping cart moving at a velocity of 0.5 m/s collides with a store wall and stops. The momentum of the shopping cart
Answer: decreases.
A ball is thrown downward from the top of a building with an initial speed of 25 m/s. It strikes the ground after 2.0 s. How high is the building?
A ball is thrown downward from the top of a building with an initial speed of 25 m/s. It strikes the ground after 2.0 s. How high is the building?
Answer: 30 m
A car travels at 15 m/s for 10 s. It then speeds up with a constant acceleration of 2.0 m/s^2 for 15 s. At the end of this time, what is its velocity?
A car travels at 15 m/s for 10 s. It then speeds up with a constant acceleration of 2.0 m/s^2 for 15 s. At the end of this time, what is its velocity?
Answer: 45 m/s
A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. What is her average speed for the trip?
A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. What is her average speed for the trip?
Answer: 88 km/h
If you run a complete loop around an outdoor track (400 m), in 100 s, your average velocity is
If you run a complete loop around an outdoor track (400 m), in 100 s, your average velocity is
Answer: zero
Which would hit the ground first if dropped from the same height in a vacuum--a feather or a metal bolt?
Which would hit the ground first if dropped from the same height in a vacuum--a feather or a metal bolt?
Answer: They would hit at the same time
A baseball catcher throws a ball vertically upward and catches it in the same spot as it returns to the mitt. At what point in the ball's path does it experience zero velocity and nonzero acceleration at the same time?
A baseball catcher throws a ball vertically upward and catches it in the same spot as it returns to the mitt. At what point in the ball's path does it experience zero velocity and nonzero acceleration at the same time?
Answer: at the top of its path
Which of the following statements applies to the motion of a ball rising and then falling in free fall?
Which of the following statements applies to the motion of a ball rising and then falling in free fall?
I. the ball has constant acceleration as it moves upward.
II. the ball has constant acceleration at the top of its path.
III. The ball has constant acceleration as it moves downward.
Acceleration due to gravity is also called
Acceleration due to gravity is also called
Answer: free-fall acceleration
When a car's velocity is negative and its acceleration is negative, what is happening to the car's motion?
When a car's velocity is negative and its acceleration is negative, what is happening to the car's motion?
Answer: the car speeds up
When a car's velocity is positive and its acceleration is negative, what is happening to the car's motion?
When a car's velocity is positive and its acceleration is negative, what is happening to the car's motion?
Answer: the car slows down
If you know the acceleration of a car, its initial velocity, and the time interval, which of the following can you predict?
If you know the acceleration of a car, its initial velocity, and the time interval, which of the following can you predict?
Answer: the direction of the car's final velocity, the magnitude of the car's final velocity, and the displacement of the car
The graph above describes the motion of a cyclist. During the interval shown (velocity vs. time graph, a line with a positive slope) the cyclist is
The graph above describes the motion of a cyclist. During the interval shown (velocity vs. time graph, a line with a positive slope) the cyclist is
Answer: speeding up
The graph above describes the motion of a cyclist. The graph illustrates that the acceleration of the cyclist (velocity vs. time graph, a line with a positive slope)
The graph above describes the motion of a cyclist. The graph illustrates that the acceleration of the cyclist (velocity vs. time graph, a line with a positive slope)
Answer: is constant
What is the SI unit of acceleration?
What is the SI unit of acceleration?
Answer: m/s^2
Which of the following is the equation for acceleration?
Which of the following is the equation for acceleration?
Answer: a = change in velocity/ change in time
Acceleration is defined as
Acceleration is defined as
Answer: the rate of change of velocity
According to the graph above, during which interval does the cat have the greatest positive velocity?
According to the graph above, during which interval does the cat have the greatest positive velocity?
Answer: displacement vs. time graph, wherever the graph is increasing the most.
According to the graph above, the cat has the fastest speed during which interval?
According to the graph above, the cat has the fastest speed during which interval?
Answer: steepest slope in a displacement vs. time graph
According to the graph above, during which interval is the cat at rest?
According to the graph above, during which interval is the cat at rest?
Answer: In a displacement vs time graph, any points where the graph is horizontal indicates rest.
Suppose you are given a position versus time graph. The slope of a line drawn tangent to a point on the curve of this graph describes what quantity?
Suppose you are given a position versus time graph. The slope of a line drawn tangent to a point on the curve of this graph describes what quantity?
Answer: instantaneous velocity
Which of the following is the equation for average velocity?
Which of the following is the equation for average velocity?
Answer: change in x/change in time = average velocity
The driver of a car traveling 110 km/h slams on the brakes so that the car undergoes a constant acceleration, skidding to a complete stop in 4.5 sec. What is the most accurate plot of velocity versus time for the braking car?
The driver of a car traveling 110 km/h slams on the brakes so that the car undergoes a constant acceleration, skidding to a complete stop in 4.5 sec. What is the most accurate plot of velocity versus time for the braking car?
Answer: Straight line with a negative slope.
The driver of a car traveling 110 km/h slams on the brakes so that the car undergoes a constant acceleration, skidding to a complete stop in 4.5 sec. If the car skids in a straight line for the entire length of the stopping distance, how long are its skid marks?
The driver of a car traveling 110 km/h slams on the brakes so that the car undergoes a constant acceleration, skidding to a complete stop in 4.5 sec. If the car skids in a straight line for the entire length of the stopping distance, how long are its skid marks?
Answer: 7.0 x 10^1 km
The driver of a car traveling 110 km/h slams on the brakes so that the car undergoes a constant acceleration, skidding to a complete stop in 4.5 sec. What is the average acceleration of the car during braking?
The driver of a car traveling 110 km/h slams on the brakes so that the car undergoes a constant acceleration, skidding to a complete stop in 4.5 sec. What is the average acceleration of the car during braking?
Answer: 26.9 m/s^2
John goes for a run. From his house, he jogs north for exactly 5.0 min at an average speed of 8.0 km/h. He continues north at a speed of 12.0 km/h for the next 30.0 min. He then turns around and jogs south at a speed of 15.0 km/h for 15.0 min. Then he jogs south for another 20.0 min at 8.0 km/h. He walks the rest of the way home. What is the correct plot of total distance as a function of time for John's jog?
John goes for a run. From his house, he jogs north for exactly 5.0 min at an average speed of 8.0 km/h. He continues north at a speed of 12.0 km/h for the next 30.0 min. He then turns around and jogs south at a speed of 15.0 km/h for 15.0 min. Then he jogs south for another 20.0 min at 8.0 km/h. He walks the rest of the way home. What is the correct plot of total distance as a function of time for John's jog?
Answer: The graph increases the whole time in almost a straight line.
John goes for a run. From his house, he jogs north for exactly 5.0 min at an average speed of 8.0 km/h. He continues north at a speed of 12.0 km/h for the next 30.0 min. He then turns around and jogs south at a speed of 15.0 km/h for 15.0 min. Then he jogs south for another 20.0 min at 8.0 km/h. He walks the rest of the way home. How far will John have to walk to get home after he finishes jogging?
John goes for a run. From his house, he jogs north for exactly 5.0 min at an average speed of 8.0 km/h. He continues north at a speed of 12.0 km/h for the next 30.0 min. He then turns around and jogs south at a speed of 15.0 km/h for 15.0 min. Then he jogs south for another 20.0 min at 8.0 km/h. He walks the rest of the way home. How far will John have to walk to get home after he finishes jogging?
Answer: 0.25 km
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