What's this?
It's a lever.
What's this?
It's balance.
What's this?
It's effort.
What's this?
It's a fulcrum.
What's this?
It's friction.
What's this?
It's force.
What's this?
It's mass.
What's this?
It's speed.
Does ice have more or less friction than sand?
It has less friction.
Does a balloon have more or less mass than a stone?
It has less mass than a stone.
