Final answer:
A shaft attached to a wheel so that both rotate is known as a 'wheel and axle.' It's a type of simple machine that functions similarly to a lever, with the mechanical advantage given by the ratio of the wheel's radius to the axle’s radius.
Step-by-step explanation:
A shaft attached to a wheel of a larger diameter so that both rotate together is referred to as a wheel and axle. This setup is a classic example of a simple machine, which in many ways functions like a lever. The key difference in the case of a wheel and axle is that the effort arm, in this case represented by the wheel, can rotate fully around the fulcrum, which is the axle's center.
When force is applied to the rim of the wheel, due to its larger radius compared to that of the axle, a greater force is transferred to any load attached to or moved by the axle. The mechanical advantage (MA) of the system is calculated by dividing the radius of the wheel by the radius of the axle. This concept is important in various applications, including cranks and gear systems found in everyday machinery like cars.
For instance, if an axle's radius is 2.0 cm and the wheel's radius is 24.0 cm, the mechanical advantage would be 0.083. This implies that much greater effort would be required at the axle to produce force at the wheel's rim, demonstrating the inverse relationship between force and distance in simple machines.