Momentum and Its Conservation Review Momentum is a ___ quantity scalar 2.vector Momentum can be calculated by multiplying mass by 1.Acceleration 2.Velocity 3.Impulse 4.Time If no net force acts on a body 1.The velocity of the body in constant 2.The body is accelerating 3.The momentum of the body is zero 4.The momentum of the body is increasing The greatest change in momentum will be produced by 1.A large force acting over a long time 2.A small force acting over a short time 3.A large force acting over a short time 4.A small force acting over a long time If an object with a velocity of 50 m/s has the same momentum as that of a 10 kg mass having a velocity of 20 m/s, the mass of the object is 1.Greater than 10 kg 2.Less than 10 kg 3.10 kg Impulse can be represented by 1.v/ t 2.F t 3.Mv 4.None of these When a golfer hits a golf ball, the force exerted by the ball on the club is ___ that exerted by the club on the ball. 1.Equal to 2.Greater than 3.Less than When a golf club hits a golf ball, the change in momentum of the ball is ___ the change in momentum of the club. 1.Equal to 2.Greater than 3.Less than When a golf club hits a golf ball, the change in velocity of the ball is ___ that of the club. 1.Equal to 2.Greater than 3.Less than If an object moving at a rate of 20 m/s collides with a stationary object and the two objects move away together, the velocity of the combined objects will be 1.Greater than 20 m/s 2.Less than 20 m/s 3.20 m/s The collision described in the previous question would be classified as an ____ collision. 1.Elastic 2.Inelastic Two moving objects collide and move apart on paths that are 120 o apart. The total momentum of the objects after the collision is ___ the total momentum before the collision. 1.Equal to 2.Greater than 3.Less than If the momentum of an object changes and its mass remains constant, 1.Its velocity is changing 2.It is accelerating 3.There is a force acting on it 4.All of the above 5.None of the above The reason that crumple zones are used in cars is that they 1.Increase the force of impact in a collision 2.Decrease the momentum of a collision 3.Decrease the impulse in a collision 4.Increase the time of impact in a collision Which has the greater momentum: a 145 g baseball traveling at 40.0 m/s or a 45 g golf ball traveling at 67.0 m/s? 1.The baseball 2.The golf ball 3.Both have the same momentum What impulse is needed to stop a 45 g mass traveling at 42 m/s? N. s N. s N. s N.s A force of 500 N is used to stop an object with a mass of 50 kg moving at 2 m/s. How long will it take to bring the object to a full stop? seconds seconds seconds seconds Which type of collisions obey the law of conservation of momentum? 1.Elastic 2.Inelastic 3.Both elastic and inelastic 4.Neither elastic nor inelastic Which of the following is NOT a vector quantity? 1.Acceleration 2.Force 3.Momentum 4.Time An egg is thrown against a wall. A second egg of equal mass is thrown with the same velocity at a sheet. Which egg experiences the greater impulse? 10 1.The egg thrown at the wall. 2.The egg thrown at the sheet. 3.Both experience the same impulse A system is said to be closed if 1.No external force acts on it 2.The momentum of each object in the system remains the same 3.Objects cannot enter or leave the system 4.Objects can enter but not leave the system An internal force ___ the total momentum of a system. 1.Increases 2.Decreases 3.Does not change