Physical Science Review

A tugboat is pushing a barge into a harbor. The barge is exerting a force of 3000 N against the tugboat. Which force would most likely allow the tugboat to move the barge into the harbor?

-4500 N

Based on the tug of war pictured below, what is the net force?

10 N

A football player has a mass of 65 kg and is moving with a velocity of 5 m/s. What is the player's momentum?

325 kg • m/s

Sayid made a chart listing data of two colliding objects. According to the law of conservation of momentum, what is the missing value in the chart?

6

The table shows the relationship between the masses of two objects, the distance between the two objects, and the gravitational force between the objects. Which conclusion is supported by the data in the table?

An increase in the distance between the objects causes a greater change in the gravitational force than the same increase in mass.

Katie rolls a toy car off the end of a table. Which path will the car follow when it leaves the table?

C

In a car, how does an air bag minimize the force acting on a person during a collision?

It increases the time it takes for the person to stop.

Two objects collide and bounce apart. Assuming no outside forces act on the system, which best describes the total momentum after the collision?

It is always the same as it was before the collision.

A scientist on Earth drops a hammer and a feather at the same time an astronaut on the moon drops a hammer and a feather. Which result is expected?

The hammer hits the ground before the feather on Earth, and the hammer and feather hit at the same time on the moon.

Scientists launch a rocket, and they monitor its acceleration and the force exerted by its engines. As the rocket gets higher, the monitors show that the acceleration of the rocket is increasing but the force exerted stays the same. How do Newton's laws explain why the scientists could expect this to happen?

The mass of the rocket decreases as fuel is burned, so the acceleration increases.

Levi and Clara are trying to move a very heavy box. Levi is pushing the box with a force of 30 N, and Clara is pulling the box with a force of 50 N. The box exerts a frictional force of 65 N. Which best explains the forces?

There is a net force of 15 N allowing Levi and Clara to move the box.

Which piece of furniture will have the most inertia and give the furniture movers the most difficulty in moving?

a 75kg dining table

Which best describes a force?

a vector with magnitude and direction

Engineers are trying to improve a race car. Their goal is to increase the acceleration of the car using the same engine. Which change shows the best application of Newton's laws of motion to achieve this goal?

decreasing the mass of the car

Which refers to an object's resistance to any change in its motion?

inertia