Forces in Motion

Machine 1 performs 24 joules of work in 2 seconds. Machine 2 performs the same amount of work in half the time. Which statement is true about machines 1 and 2?

• Machine 1 and 2 used the same amount of power

• Machine 1 used more power than machine 2

• Machine 1 and 2 didn't use any power

Which object has a periodic motion?

• a sea star

• a bycicle

• a pendulum

A train travels 160 miles north in 2 hours. What is the velocity of the train?

How do electricity and magnetism act on different objects?

• they can push objects

• they can pull objects

• they can push or pull objects

Mark all the simple machines

• wheel and axle

• lever

• motor

• catapult

• airplane

When you ride a roller coaster, what makes your body rise out of its seat at the top of a hill?

• gravity

• inertia

• friction

A train hits a bug. What effect does the bug have on the train?

• the bug has no effect on the train

• the bug hits the train with less force than the force which the train hits the bug

• the bug hits the train with more force than the force which the train hits the bug

Which force keeps a satellite in orbit?

• friction

• gravity

• inertia

• magnetism

Complete the statement.

The greater the net force acting on an object, ____________________________________

Which complex machine uses mainly human force to operate the simple machines in it?

• bicyle

• car

• go cart