Exam 7: Impulse and Momentum

A 4.0-kg block slides along a frictionless surface with a constant speed of 5.0 m/s as shown.Two seconds after it begins sliding, a horizontal, time-dependent force is applied to the mass.The force is removed eight seconds later.The graph shows how the force on the block varies with time. -What is the magnitude of the total impulse of the force acting on the block?

A comet fragment of mass 1.96 × 10¹³ kg is moving at 6.50 × 10⁴ m/s when it crashes into Callisto, a moon of Jupiter.The mass of Callisto is 1.08 × 10²³ kg.The collision is completely inelastic. -How much kinetic energy was released in the collision?

A 2.0-kg pistol fires a 1.0-g bullet with a muzzle speed of 1000 m/s.The bullet then strikes a 10-kg wooden block resting on a horizontal frictionless surface.The block and the embedded bullet then slide across the surface. -What is the speed of the "bullet + block" system immediately after the bullet is embedded in the block?

Which one of the following statements concerning momentum is true?

A 2-kg stone falls 100 meters near the surface of the earth.It strikes the ground without any rebound thereby making a completely inelastic collision with the earth.Approximately how much kinetic energy is transferred to the earth in this process?

A projectile is launched with a momentum of 200 kg • m/s and 1000 J of kinetic energy.What is the mass of the projectile?

A 0.050-kg lump of clay moving horizontally at 12 m/s strikes and sticks to a stationary 0.15-kg cart that can move on a frictionless air track.Determine the speed of the cart and clay after the collision.

A stationary bomb explodes in space breaking into a number of small fragments.At the location of the explosion, the net force due to gravity is zero newtons.Which one of the following statements concerning this event is true?

Which one of the following is characteristic of an inelastic collision?

A space vehicle of mass m has a speed v.At some instant, it separates into two pieces, each of mass 0.5m.One of the pieces is at rest just after the separation. -How much work was done by the internal forces that caused the separation?

A 0.015-kg marble moving to the right at 0.40 m/s has a head-on, elastic collision with a 0.045-kg marble sitting at rest on a smooth, level surface.Which of the following are the correct magnitudes and directions of the velocities of the two marbles after the collision? 0.015 kg marble 0.045 kg marble

A rock is dropped from a high tower and falls freely under the influence of gravity.Which one of the following statements concerning the rock as it falls is true? Neglect the effects of air resistance.

A machine gun fires 25-g bullets at the rate of 4 bullets per second.The bullets leave the gun at a speed of 1000 m/s.What is the average recoil force experienced by the machine gun?

While on an interplanetary mission, a 58.5-kg astronaut is floating toward the front of her ship at 0.15 m/s, relative to the ship.She wishes to stop moving, relative to the ship.She decides to throw away the 2.50-kg book she's carrying.What should the approximate speed and direction of the book be to achieve her goal?

A 1000-kg car traveling east at 20 m/s collides with a 1500-kg car traveling west at 10 m/s.The cars stick together after the collision.What is the common velocity of the cars after the collision?

While a car is stopped at a traffic light in a storm, raindrops strike the roof of the car.The area of the roof is 5.0 m².Each raindrop has a mass of 3.7 × 10^-4 kg and speed of 2.5 m/s before impact and is at rest after the impact.If, on average at a given time, 150 raindrops strike each square meter, what is the impulse of the rain striking the car?

A 160-kg space probe is moving in the positive x direction at 18 km/s when it encounters a time-dependent force directed in the negative x direction.The force is as follows: Determine the final speed of the space probe.

Which one of the following statements concerning center of mass is true?

Two asteroids are drifting in space with trajectories shown.Assuming the collision at point O between them is completely inelastic, at what angle from its original direction is the larger asteroid deflected?

A 100-kg fisherman and a 500-kg supply crate are on a frozen pond that is essentially frictionless.The man and the crate are initially separated by a distance of 600 meters.The fisherman uses a very light rope to pull the crate closer to him.How far has the man moved when the crate reaches the fisherman?