Lab: Conservation of Linear Momentum — Unit test Answers

Momentum data about the same objects in the same closed system is shown below.

A car is moving east along a straight, level road at a constant velocity. Which forces form an action/reaction force pair?

In a lab, two identical lab carts (m = 1.0 kg) travel toward each other, each with a speed of 2 m/s. The cars collide, and one cart moves to the right with a speed of 3 m/s and the other moves left with a speed of 2 m/s.

An empty 2,500 kg train car is headed northbound at a velocity of 5 m/s. Ahead of the first car, an empty 1,500 kg car is headed northbound on the same track at 1 m/s. The faster train bumps into the slower one, and they combine into one train.What is the velocity of the two-car train?

According to Newton’s first law of motion, what will an object in motion do when no external force acts on it?

A sports car and a minivan run out of gas and are pushed to the side of the road. Which is easier to push, and why?

Four identical lab carts each have a mass of 200 kg. Different masses are added to the carts and the velocities are measured. All carts move to the right.Which cart has the greatest momentum?

A box is sitting on the floor. The box was then pulled with a force, Ft. The box did not move. The free-body diagram of the box is shown.

A ball strikes a wall. It exerts a force of 10 N to the left against the wall and bounces off. What force does the wall exert on the ball?

Chang sees the following formula on a website about Newton’s second law. a =

What are possible units for impulse? Check all that apply.

In deep space, there is very little friction. Once they launch a probe into deep space, where there are no external forces acting on it, scientists shut the probe’s engines off because the scientists want the probe to

A 57 g tennis ball is traveling at 45 m/s to the right, when it hits a racket. The ball reverses direction and travels at 33 m/s. The ball is in contact with the racket for 0.0085 s.

A 35-gram stainless steel ball on a track is moving at a velocity of 9 m/s. On the same track, a 75-gram stainless steel ball is moving at a velocity of –7 m/s. After colliding, the 35-gram ball moves at a velocity of –15 m/s. Assume there is no net force on the system.What is the velocity of the 75-gram ball after the collision? Round to the nearest tenth.

A box that has a mass of 80 kg slides down a ramp with a 30 degree angle. The free-body diagram shows the forces acting on the box.