Exam 6: Momentum, Impulse, and Collisions

A 70-kg swimmer dives horizontally off a 500-kg raft.The diver's speed immediately after leaving the raft is 6.0 m/s.A micro-sensor system attached to the edge of the raft measures the time interval during which the diver applies an impulse to the raft just prior to leaving the raft surface.If the time interval is read as 0.25 s,what is the magnitude of the average horizontal force by diver on the raft?

An unfueled 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 160 m/s after the burn,what impulse is experienced by the rocket sled?

A uranium nucleus (mass 238 units)at rest decays into a helium nucleus (mass 4.0 units)and a thorium nucleus (mass 234 units).If the speed of the helium nucleus is 5.5 × 10⁵ m/s,what is the speed of the thorium nucleus?

Three satellites are launched into space connected together.Once in deep space,an explosive charge separates the three satellites and they move apart.The satellites each have different masses with m₁ < m₂ < m₃.Which of the following statements is always true?

A 0.10-kg ball is moving at 7.0 m/s when it is hit by a bat,causing it to reverse direction and have a speed of 12.0 m/s.What is the change in the magnitude of the momentum of the ball?

A 2 900-kg truck moving at 11.0 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?

A helicopter stays aloft by pushing large quantities of air downward every second.What mass of air must be pushed downward at 35.0 m/s every second to keep a 1 500-kg helicopter aloft?

If a glass of water is on a table with a piece of paper under it,it is relatively easy to pull the paper out without disturbing the glass very much if the pull is done very quickly.This is because,with a quick pull:

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.

A high-diver of mass 59.8 kg jumps off a board 10.0 m above the water.If,1.00 s after entering the water his downward motion is stopped,what average upward force did the water exert?

During a snowball fight two balls with masses of 0.30 and 0.70 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 12.0 m/s.What is the speed of the 1.0-kg mass immediately after collision?

A 75.0-kg swimmer dives horizontally off a 465-kg raft initially at rest.If the diver's speed immediately after leaving the raft is 5.00 m/s,what is the corresponding raft speed?

A rocket with initial mass of 3.0 × 10⁴ kg fires its engines at t = 0.The exhaust speed of the rocket is 3.9 × 10³ m/s.If the velocity of the rocket at t = 200 s is 1 500 m/s,how much fuel did it consume?

Two masses m₁ and m₂,with m₁ = 3 m₂,undergo a head-on elastic collision.If the particles were approaching with speed v before the collision,with what speed are they moving apart after collision?

A 26.0-g bullet moving at 1 200 m/s is fired through a one-kg block of wood emerging at a speed of 200 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?

Lonnie pitches a baseball of mass 0.500 kg.The ball arrives at home plate with a speed of 35.0 m/s and is batted straight back to Lonnie with a return speed of 50.0 m/s.If the bat is in contact with the ball for 0.055 s,what is the impulse experienced by the ball?

A crane drops a 0.250-kg steel ball onto a steel plate.The ball's speeds just before impact and after are 4.00 m/s and 3.70 m/s,respectively.If the ball is in contact with the plate for 0.035 s,what is the magnitude of the average force that the ball exerts on the plate during impact?

A soccer ball (mass = 0.43 kg)is moving at a speed of 20 m/s when it is kicked with a force of 300 N resulting in it going in the opposite direction with the same speed as before.What is the magnitude of the impulse delivered to the ball?

Three masses are moving along the x-axis.Their masses and velocities are ​m​₁ = ​m​ with ​v_​1 = ​v​,​m_​2 = 2​m with v₂ = 2v,and m₃ = 3m with v₃ = -3v ​(the minus sign indicating this velocity is in the negative x-direction).The three masses collide and stick together in a completely inelastic collision.What is the resultant velocity of the combined mass?

The impulse experienced by a body is equivalent to its change in: