Types of Forces

There is less friction over smoother surfaces than rough surfaces.

• True

• False

The moon is a large body so it exerts gravity on an astronaut in a space shuttle orbiting it. The astronaut is small compared to the moon so it cannot gravity on it.

• True

• False

In the absence of friction, an object moving along a horizontal surface would continue to move at an increasing speed forever!

• True

• False

If gravity is the only factor present, then all dropped objects will fall at different speeds depending on their size.

• True

• False

The gravity of the Earth and other large objects are strong enough to be observed, but usually gravitational force from small bodies are too weak to be felt.

• True

• False

_______ is the force air exerts against a moving object causing it to slow down.

• gravity

• drag

• weight

• terminal velocity

A crumpled piece of paper can fall at the same time as a stone because of Earth's pull of gravity.

• True

• False

Friction opposes motion or keeps an object from starting to move.

• True

• False

The measure of gravitational force acting on an object is called _______.

• drag

• weight

• terminal velocity

• gravity

• friction

Objects that move in Earth's atmosphere is affected by ________ and ________.

• drag

• weight

• terminal velocity

• gravity

• friction