Front

air resistance

Back

A form of friction that can be helpful, such as in skydiving, to reduce speed before impact.

Front

friction

Back

A force that can be helpful or unhelpful, such as making a bike harder to pedal.

Front

upthrust

Back

The upward force exerted by a fluid on a submerged object.

Front

newton

Back

The SI unit of force.

Front

mass

Back

The amount of matter in an object.

Front

equilibrium

Back

A state in which opposing forces or influences are balanced.

Front

energy

Back

The ability to do work.

Front

accelerate

Back

To increase in speed.

Front

gravity

Back

The force that attracts a body toward the center of the earth.

Front

water resistance

Back

The force on an object moving through water that causes it to slow down (also known as drag).