Forces and Motion

What is a force?

• Something that characters from Star Wars have.

• An attraction between opposite magnetic poles.

• A push or a pull.

• Distance divided by time.

Forces that are opposite in direction but not equal in size are...

• balanced forces

• unbalanced forces

• frictional forces

• catastrophic forces

Balanced forces are...

• opposite in direction but not equal in size.

• not opposite in direction and not equal in size.

• opposite in direction and equal in size.

• forces that keep you standing up without falling over.

What kind of forces do you have to have in order to have motion?

• Opposite

• Gravitational

• Balanced

• Unbalanced

What unit is force measured in?

• Watts

• Joules

• Newtons

• m/s²

The force exerted by every object in the universe on every other object is called _______________.

• friction

• work

• acceleration

• gravity

The amount of gravitational force between two objects depends on what two things?

• The masses of the objects and the distance between them.

• The masses of the objects and their speed.

• The distance between the objects and how large they are.

• The friction between the objects and the distance between them.

You have two satellites of equal mass orbiting the Earth. Satellite A is 150 miles above the Earth, and satellite B is 200 miles above the Earth. Upon which one will the pull of Earth's gravity be greater?

• Satellite A

• Satellite B

A satellite with a mass of 1,000 kg and an asteroid with a mass of 50,000 kg are both 300 miles from the Earth. Upon which object is the pull of Earth's gravity greater?

• the satellite

• the asteroid

Why are all planets and stars spheres?

• Because a spherical shape gives planets and stars less friction as they fly through space.

• Because square planets and stars would look dumb.

• Because, since gravity pulls toward the center of an object equally in all directions, the only shape that you can have is a sphere.

• Because the acceleration due to gravity is different on all planets.