________ is having two opposites that work differently.

A magnet's force is stronger at the center.

A electromagnet is a device that uses both electricity and magnetism force.

A wheel and axle overcomes friction using a ___________

An incline plane is a simple machine that uses a slope.

Gravity is the strongest at the center of an object.

_______ is the attracting force of two objects.

Lubricants are substances that are greasy and slippery.

The force of gravity on an object is called __________.

Which surface increases friction?

The base of a building is called ___________.

The skeleton of a building is called the ___________.

A ________ is a machine that lifts heavy things.

The fulcrum of the lever balances and holds the weight.

A machine is a device that makes work easier.

__________ is the attracting and repelling force.

A screw is an example of a wedge.

The Earth's gravity is more than the moon.