Motorized Simple Machines.
The entire fourth grade with some helpers from 5th built projects.
They carefully measured axles and counted studs on beams to make sure they used the right pieces.
Theses bridges are draw bridges.
Maybe the car can go on the bridge.
This might be a boat under the bridge.
Merry go rounds can use pulleys
or
chains.
They can be motoized or go by hand.
Conveyors can move things.
Two can be used together.
The gate is motorized.
