Physics momentum review

A 3 kg mass is positioned at (0, 8), and a 1 kg mass is positioned at (12, 0). What are the coordinates of a 4 kg mass which will result in the center of mass of the system of three masses being located at the origin (0, 0)? (-6, -3) (-12, -8) (3, 6) (-3, -6)

(-3, -6)

Which of the following equations can be used to directly calculate the change in an object's momentum? p = mv p = m/v p = FDt p = F(change in)t (change in)p = F(change in)t

(change in)p = F(change in)t

A red ball with a velocity of +3.0 m/s collides head-on with a yellow ball of equal mass moving with a velocity of -2.0 m/s. What is the velocity of the yellow ball after the collision? zero +5.0 m/s -2.0 m/s +3.0 m/s

+3.0 m/s

A billiard ball is moving in the x-direction at 30.0 cm/s and strikes another billiard ball moving in the y-direction at 40.0 cm/s. As a result of the collision, the first ball moves at 50.0 cm/s, and the second ball stops. What is the change in kinetic energy of the system as a result of the collision? 0 some positive value some negative value No answer above is correct.

0

A 3.0-kg object moves to the right at 4.0 m/s. It collides in a perfectly inelastic collision with a 6.0 kg object moving to the left at 2.0 m/s. What is the total kinetic energy after the collision? 0 J 36 J 24 J 72 J

0 J

A 20-g bullet moving at 1 000 m/s is fired through a one-kg block of wood emerging at a speed of 100 m/s. What is the kinetic energy of the block that results from the collision if the block had not been moving prior to the collision and was free to move? 10 kJ 9.8 kJ 0.16 kJ 0.018 kJ

0.16 kJ

A 2 500-kg truck moving at 10.00 m/s strikes a car waiting at a traffic light, hooking bumpers. The two continue to move together at 7.00 m/s. What was the mass of the struck car? 1 730 kg 1 550 kg 1 200 kg 1 070 kg

1 070 kg

A 1-N apple falls to the ground. The apple hits the ground with an impact force of 1 N. 2 N. 4 N. 9.8 N. Not enough information to say

1 N.

Two friends with mass 60.0 kg and 40.0 kg run directly toward each other with speeds 3.0 m/s and 2.0 m/s respectively. If they hold on to each other after they collide, their combined speed just after the collision will be: 0 m/s 1.0 m/s 1.6 m/s 2.0 m/s

1.0 m/s

A ball, of mass 100. g, is dropped from a height of 12. m. Its momentum when it strikes the ground is 2.4 kg∙m/s. 4.8 kg∙m/s. 1.8 kg∙m/s. 1.5 kg∙m/s. 3.3 kg∙m/s.

1.5 kg∙m/s.

A 1 000-kg experimental rocket sled on level frictionless rails is loaded with 50 kg of propellant. It exhausts the propellant in a 20-s "burn." If the rocket, initially at rest, moves at 150 m/s after the burn, what impulse is experienced by the rocket sled? 1.1 ´ 10^5 kg×m/s 1.6 ´ 10^5 kg×m/s 1.5 ´ 10^5 kg×m/s 1.9 ´ 10^5 kg×m/s

1.5 ´ 10^5 kg×m/s

A 60. gram toy rocket achieves a speed of 80. m/s after 3.0 s, when fired straight up. What is the average total force on the rocket during the 3 s? 1.6 N 3.4 N 3.2 N 2.2 N 1.2 N

1.6 N

A 90-kg halfback running north with a speed of 10 m/s is tackled by a 120-kg opponent running south at 4 m/s. The collision is perfectly inelastic. Compute the velocity of the two players just after the tackle. 3 m/s south 2 m/s south 2 m/s north 3 m/s north

2 m/s north

A toy rocket, of mass 60 g, achieves a velocity of 80 m/s after 3.0 s when fired straight up. What average thrust force does the rocket engine exert? 3.3 N 3.4 N 1.2 N 1.6 N 2.2 N

2.2 N

A 0.12-kg ball is moving at 6 m/s when it is hit by a bat, causing it to reverse direction and have a speed of 14 m/s. What is the change in the magnitude of the momentum of the ball? 0.39 kg×m/s 0.42 kg×m/s 1.3 kg×m/s 2.4 kg×m/s

2.4 kg×m/s

A 6 kg block moves with a constant speed 5 m/s on a horizontal frictionless surface and collides elastically with an identical block initially at rest. The second block collides and sticks to the last 6 kg block which was initially at rest. What is the speed of the third 6 kg block after the second collision? zero 2 m/s 2.5 m/s 5 m/s

2.5 m/s

A proton, of mass m and speed v, strikes an alpha-particle (which consists of 2 protons and 2 neutrons) at rest. If the collision is completely elastic, what speed will the α-particle have after the collision? (Assume the neutron's mass equals the proton's mass.) 2/3 v 5/3 v 2/5 v 3/2 v zero

2/5 v

Jerome pitches a baseball of mass 0.20 kg. The ball arrives at home plate with a speed of 40 m/s and is batted straight back to Jerome with a return speed of 60 m/s. What is the magnitude of change in the ball's momentum? 4.0 kg×m/s 8.0 kg×m/s 18 kg×m/s 20 kg×m/s

20 kg×m/s

A baseball infielder, mass 75.0 kg, jumps up with velocity 3.00 m/s and catches a 0.150-kg baseball moving horizontally at 50.0 m/s. Of the following, which is closest to the final momentum of the system, infielder and baseball? 225 kg×m/s 228 kg×m/s 230 kg×m/s 233 kg×m/s

225 kg×m/s

Two astronauts, of masses 60. kg and 80. kg, are initially at rest in outer space. They push each other apart. What is their separation after the heavier astronaut has moved 12. m? 16. m 28. m 24. m 9. m 21. m

28. m

A 3. kg ball of putty moving at 1 m/s collides and sticks to a 2 kg ball initially at rest. The putty and ball then move with a momentum of 4 N-s. 1 N-s. 2 N-s. 0 N-s. 3 N-s.

3 N-s.

During a snowball fight two balls with masses of 0.4 and 0.6 kg, respectively, are thrown in such a manner that they meet head-on and combine to form a single mass. The magnitude of initial velocity for each is 15 m/s. What is the speed of the 1.0-kg mass immediately after collision? zero 3 m/s 6 m/s 9 m/s

3 m/s

At what speed must a 150-kg football player be moving to have the same momentum as a 15.0-g bullet traveling at 300 m/s? 30.0 m/s 3.00 m/s 10.0 m/s 3.00 cm/s 1.00 m/s

3.00 cm/s

A 3 kg ball is dropped onto a concrete floor. What is the magnitude of the ball's change in momentum if its speed just before striking the floor is 7 m/s and its rebound speed is 3 m/s? 10 kg-m/s 15 kg-m/s 30 kg-m/s 60 kg-m/s

30 kg-m/s

A 0.10-kg object moving initially with a velocity of +0.20 m/s makes an elastic head-on collision with a 0.15-kg object initially at rest. What percentage of the original kinetic energy is retained by the 0.10-kg object? 4% -4% 50% 96%

4%

A golf club exerts an average force of 1000 N on a 0.045-kg golf ball which is initially at rest. The club is in contact with the ball for 1.8 ms. What is the speed of the golf ball as it leaves the tee? 30 m/s 50 m/s 35 m/s 40 m/s 45 m/s

40 m/s

Astronaut Jennifer's lifeline to her spaceship comes loose and she finds herself stranded, "floating" 100. m from the mothership. She throws her 2.00 kg wrench at 20.0 m/s in a direction away from the ship. If she and her spacesuit have a combined mass of 200. kg how long does it take her to coast back to her spaceship? 750. s 500. s 2.50 minutes 1000. s 250. s

500. s

In a game of pool, the white cue ball hits the #9 ball and is deflected at a 35° angle to the original line of motion. What is the angle of deflection below the original line of motion for the #9 ball? 90° 75° 35° 55°

55°

A 2-kg ball is thrown at 3 m/s. What is the ball's momentum? 2 kg·m/s 3 kg·m/s 6 kg·m/s 9 kg·m/s none of the above

6 kg·m/s

Car A (mass = 1000 kg) moves to the right along a level, straight road at a speed of 6.0 m/s. It collides directly with car B (mass = 200 kg) in a completely inelastic collision. What is the momentum after the collision if car B was initially at rest? 8.0 KN-s to the left 10. KN-s to the right 2.0 KN-s to the right 6.0 KN-s to the right zero

6.0 KN-s to the right

A 30. kg child stands at one end of a floating 20. kg canoe that is 10. ft long. The child walks to the other end of the canoe. How far does the canoe move in the water assuming water friction is negligible? 8.0 ft 4.0 ft 6.0 ft 2.0 ft 10. ft

6.0 ft

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, 0. 12 m/s. 3.0 m/s. 6.0 m/s.

6.0 m/s.

https://online.theinpaint.com/2821887/uA0g1aHQ/ A bullet of mass 20. g, traveling at 350. m/s, strikes a steel plate at an angle of 30.° with the plane of the plate. It ricochets off at the same angle, at a speed of 320. m/s, as shown in Fig. 6-3. What is the magnitude of the impulse that the wall gives to the bullet? 0.52 N∙s 0.30 kN∙s 4.3 N∙s 6.7 N∙s 0.30 N∙s

6.7 N∙s

Two astronauts, with masses 60. and 80. kg, are initially at rest in outer space. They push each other apart. How far has the heavier astronaut moved when the lighter astronaut has moved 12. m? 9.0 m 12. m 16. m 21. m 7.0 m

9.0 m

Which of the following has the largest momentum? A large truck parked in a parking lot A tightrope walker crossing Niagara Falls The science building at your school A pickup truck traveling down the highway A dog running down the street

A pickup truck traveling down the highway

(Multiple answers) Two lab carts are on a frictionless track, attached by a spring. The carts are pushed together by a student in a Physics lab, compressing the spring fully. The student lets go of the carts and they move in opposite directions as the spring extends. Which of the following statements describes what happens to the car/spring system after the cars are released? The kinetic energy remains constant. The kinetic energy increases. The momentum remains constant. The momentum increases.

A. The kinetic energy increases. B. The momentum remains constant.

(Multiple answers) Two astronauts are in the space shuttle, floating next to each other. One astronaut pushes on the other, sending him across the shuttle bay. The first astronaut doesn't move. Which physics laws were violated in this scenario? Conservation of Energy. Newton's First Law. Correct! Conservation of Momentum. Newton's Third Law.

Conservation of Momentum. Newton's Third Law.

If all people, animals, trains and trucks all over the world began to walk or run towards the east, then Earth would spin a bit slower. Earth's spin would not be affected at all. Earth would spin a bit faster.

Earth would spin a bit slower.

Collisions in which kinetic energy is conserved are said to be inelastic collisions. True False

False

In an inelastic collision, the initial kinetic energy is less than the final kinetic energy. True False

False

The impulse delivered to an object is equal to the change in the object's velocity. True False

False

Consider two unequal masses, M and m. Which of the following statements is false? If a uniform rod of mass m were to join the two masses, this would not alter the position of the center of mass of the system without the rod present. It is possible for the center of mass to lie within one of the objects. The center of mass is closer to the larger mass. The center of mass lies on the line joining the centers of each mass.

If a uniform rod of mass m were to join the two masses, this would not alter the position of the center of mass of the system without the rod present.

Which of the following is an accurate statement? If an object is acted on by a non-zero net external force, its momentum will not remain constant. If the kinetic energy of an object is doubled, its momentum will also double. The momentum of a projectile is constant. The momentum of a moving object is constant.

If an object is acted on by a non-zero net external force, its momentum will not remain constant.

Which of the following has units of momentum? kg-s/m kg-m2/s kg-m2/s2 J-s/m N-m

J-s/m

In an elastic collision, if the momentum is conserved, then which of the following statements is true about kinetic energy? Kinetic energy is lost. Kinetic energy is gained. Kinetic energy is also conserved. none of the above

Kinetic energy is also conserved.

The dimensional equivalence of the quantity "momentum" in terms of the fundamental quantities (mass, length, time) is: MLT^-1. ML2T^-2. MLT. MLT^-2.

MLT^-1.

When the velocity of a moving object is quadrupled, which of the following is also quadrupled? Kinetic energy Momentum Potential energy Acceleration

Momentum

A lump of clay is thrown at a wall. A rubber ball of identical mass is thrown with the same speed toward the same wall. Which statement is true? The clay experiences a greater change in momentum than the ball. The ball experiences a greater change in momentum than the clay. The clay and the ball experience the same change in momentum. It is not possible to know which object has the greater change in momentum.

The ball experiences a greater change in momentum than the clay.

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. Both the child and the bike have the same momentum. The bike has a greater momentum than the child. The child has a greater momentum than the bike. Neither the child nor the bike has momentum.

The child has a greater momentum than the bike.

Neglecting gravity, doubling the exhaust velocity from a single stage rocket initially at rest changes the final velocity attainable by what factor? Assume all other variables, such as the mass of the rocket and the mass of the fuel, do not change. The final velocity stays the same. The final velocity doubles. The final velocity increases by a factor of 0.693. The final velocity increases by a factor of 0.310.

The final velocity doubles.

Some automobiles have air bags installed on their dashboards as a safety measure. The impact of a collision causes the bag to inflate, and it then cushions a passenger's head when he is thrown forward in the car. Suppose that such a bag could lengthen the collision time between one's head and the dashboard by a factor of 10. What effect would this have on the force exerted on the head? The force would be reduced by a factor of about 10. The force would be reduced by a factor of about 3. The force would not be reduced, but the energy transferred to the head would be, thereby minimizing the damage done. The force would be reduced by a factor of about 100. The force would be reduced by a factor of about 1000.

The force would be reduced by a factor of about 10.

Which has more momentum, a large truck moving at 30 miles per hour or a small truck moving at 30 miles per hour? Both have the same momentum. The small truck The large truck

The large truck

When comparing the momentum of two moving objects, which of the following is correct? The object with the higher velocity will have less momentum if the masses are equal. The more massive object will have less momentum if its velocity is greater. The less massive object will have less momentum if the velocities are the same. The more massive object will have less momentum if the velocities are the same.

The less massive object will have less momentum if the velocities are the same.

A piece of putty and a rubber ball have the same mass. If you drop them from the same height, which object will produce a greater impulse and why? The silly putty will produce a greater impulse because it will bounce. The rubber ball will produce a greater impulse because it will bounce. The silly putty will produce a greater impulse because it will stop when it hits the ground. The rubber ball will produce a greater impulse because it will stop when it hits the ground.

The rubber ball will produce a greater impulse because it will bounce.

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? The small car and the truck experience the same average force. The truck experiences the greater average force. The small car experiences the greater average force. It is impossible to tell since the masses and velocities are not given.

The small car and the truck experience the same average force.

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? The truck experiences the greater average force. It is impossible to tell since the masses and velocities are not given. The small car experiences the greater average force. The small car and the truck experience the same average force.

The small car and the truck experience the same average force.

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? The total momentum before the collision is 24 kg∙m/s, and after the collision is 0 kg∙m/s. The total momentum both before and after the collision is 24 kg∙m/s. The total momentum both before and after the collision is zero. None of the above is true.

The total momentum both before and after the collision is zero.

Which of the following has the greatest momentum? a tortoise with a mass of 275 kg moving at a velocity of 0.55 m/s a hare with a mass of 2.7 kg moving at a velocity of 7.5 m/s a turtle with a mass of 91 kg moving at a velocity of 1.4 m/s a roadrunner with a mass of 1.8 kg moving at a velocity of 6.7 m/s

a tortoise with a mass of 275 kg moving at a velocity of 0.55 m/s

A car traveling along the highway needs a certain amount of force exerted on it to stop. More stopping force may be required when the car has less stopping distance. more momentum. more mass. all of the above none of the above

all of the above

The force of an apple hitting the ground depends upon the speed of the apple just before it hits. the time of impact with the ground. whether or not the apple bounces. air resistance on the apple as it falls. all of the above

all of the above

Two objects move separately after colliding, and both the total momentum and total kinetic energy remain constant. Identify the type of collision. elastic nearly elastic inelastic perfectly inelastic

elastic

While roller-skating, Granny collides with her tiny grandson Ambrose who is at rest. Ignoring any friction effects, Ambrose's speed after the collision will be greatest when Granny catches him and they both move together. he and Granny make a bouncing collision, each going in opposite directions.

he and Granny make a bouncing collision, each going in opposite directions.

The center of mass and the center of gravity coincide: if the object is in a uniform gravitational field. only if the object is symmetrical and it is in a uniform gravitational field. only if the object is symmetrical. at all times.

if the object is in a uniform gravitational field.

The momentum change of an object is equal to the: impulse acting on it. velocity change of the object. force acting on it. force acting on it times its velocity. object's mass times the force acting on it.

impulse acting on it.

See Fig. 6-1. The area under the curve on a F - t graph represents: average mass. momentum. impulse. work. power.

impulse.

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 is greater up the hill than down the hill. is greater down the hill than up the hill. remains the same throughout the ride. is zero throughout the ride.

is greater down the hill than up the hill.

What are the SI units for momentum? N·m J kg·m/s kg·m/s^2

kg·m/s

A small economy car (low mass) and a limousine (high mass) are pushed from rest across a parking lot, equal distances with equal forces. The car that receives the greater impulse is the limousine. small economy car. neither A nor B (same for each).

limousine.

The momentum of an object is defined as the object's mass times its velocity. force times the time interval. force times its acceleration. mass times it acceleration. velocity times the time interval.

mass time its velocity.

When a cannon fires a cannonball, the cannon will recoil backward because the: energy of the cannon is greater than the energy of the cannonball. momentum of the cannon is greater than the energy of the cannonball. energy of the cannonball and cannon is conserved. momentum of the cannonball and cannon is conserved. momentum of the cannon is conserved.

momentum of the cannonball and cannon is conserved.

A table tennis ball moving forward with 5 units of momentum strikes and bounces backward off a heavy bowling ball that is initially at rest and free to move. The bowling ball is set in motion with a momentum of less than 5 units. 5 units. more than 5 units. not enough information.

more than 5 units

A very light object moving with speed v collides head-on with a very heavy object at rest, in a frictionless environment. The collision is almost perfectly elastic. The speed of the heavy object after the collision is slightly less than v. equal to v. much less than v. slightly greater than v.

much less than v.

Suppose an astronaut in outer space wishes to toss a ball against a very massive and perfectly elastic concrete wall and catch it as it bounces back. If the ball is as massive as the astronaut, then the astronaut's time between catches will decrease as the game progresses. the astronaut will never catch the first bounce. the astronaut will catch one bounce only. none of the above

the astronaut will never catch the first bounce. the astronaut will catch one bounce only.

Automobile air bags reduce what during a collision? the impulse exerted upon the passenger the forces exerted upon the passenger speed of the automobile the kinetic energy transferred to the passenger

the forces exerted upon the passenger

A 100-kg football linebacker moving at 2.0 m/s tackles head-on an 80-kg halfback running Neglecting the effects due to digging in of cleats, this is a simple example of an elastic collision. neither player will drive the other backward. the halfback will drive the linebacker backward. the linebacker will drive the halfback backward.

the halfback will drive the linebacker backward.

When a collision is perfectly inelastic, then: all the kinetic energy is conserved. all the kinetic energy is gone. the participants stick together. the total momentum is zero.

the participants stick together.

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, the lighter skater has less momentum. their momenta are equal but opposite. their total momentum doubles. their total momentum decreases.

their momenta are equal but opposite.

Two swimmers relax close together on air mattresses in a pool. One swimmer's mass is 48 kg, and the other's mass is 55 kg. If the swimmers push away from each other, their total momentum triples. their momenta are equal but opposite. their total momentum doubles. their total momentum decreases.

their momenta are equal but opposite.