The wheels of the bus go round and round. This is not only a nursery rhyme but rather just the function of a wheel around an axle. A wheel and an axle is what propells cars. As you see the wheels move in unison, what keeps them moving at the same time. The answer behind this is the fact that they are connected by an axle. It is basically a ring around a cylinder. If the cylinder spins so does the ring and inturn provides propulsion for the car.
The advantage of this scenario is that the wheel makes it easier to move around. If you've ever used a wheelbarrow you have felt that it is defenitely easier to push around. In the video above, the reason the soil falls on the girl is that the lever affect on the wheelbarrow causes movement in the wheel around the axle causing it to spin and the wheelbarrow to fall.
1. Draw a design of a basic machine using an axle and wheel.
2.List a few machines that use an axle and wheel other than a car.
3.If the axle of a machine is more thin than the hole on the wheel will the axle work? Why or why not?