Motion & Forces

The independent variable on a graph can be described as the variable:

• represented on the x-axis
• causing the change in the dependent variable
• over which a scientist usually has direct control when designing the experiment
• all of the above

A race car rounds a curve on the track at a constant speed of 180 mph. While maintaining a constant speed, the car is actually accelerating because a change is taking place in the:

• distance.
• time.
• direction.
• mass.

The force of gravity on an object is called:

• mass.
• inertia.
• weight.
• volume.

A force that always tends to slow the motion of an object on a surface is:

• mass.
• weight.
• friction.
• inertia.

When a force is applied to an object it may:

• start a stationary object moving.
• stop the motion of a moving object.
• change the direction of a moving object.
• All of the above

In a game of football, a 120-kg linebacker and a 90-kg fullback, each running at 10 m/s, collide head-on at theline of scrimmage. As a result of the collision:

• the two players stop at the point of collision.
• the fullback pushes the linebacker backward because he exerts greater force.
• the linebacker pushes the fullback backward because he exerts greater force.
• the linebacker pushes the full backward because he has more inertia.

You stand on a skateboard and push off the ground with one of your feet. The reason that the skate board moves forward is that the force you apply to the skateboard:

• equals the force applied to you by the skateboard.
• is larger than the force applied by you to the skateboard.
• equals the force applied by the ground to the skateboard.
• is larger than the force applied by the ground to the skateboard.

The Moon is orbiting Earth as pictured in the diagram:

If the gravitational force between Earth and the Moon were to disappear, the Moon’s inertia would cause it to move toward:

• A
• B
• C
• D