Answer:
A. Levers are varied, but all have a few components. They all have an arm, a straight, relatively inflexible part, like the handle of an axe or the entire length of a see-saw, that needs to be unbreakable and relatively unbendable. They also have a fulcrum, or pivot point on which the lever rests and pivots.
B. inclined plane, simple machine consisting of a sloping surface, used for raising heavy bodies. The force required to move an object up the incline is less than the weight being raised, discounting friction. The steeper the slope, or incline, the more nearly the required force approaches the actual weight.
C. A pulley which has sealed ball bearings, is very strong, has a moderate weight, is not too big, has a large sheave, has a large anchor and becket hole will typically be more expensive than a pulley that does not have these characteristics.
D. A wedge is a simple machine that consists of two inclined planes, giving it a thin end and thick end. Force is applied to the thick end of the wedge, and the sloping sides of the wedge apply force to the object, cutting it or splitting it apart.
E. The main differentiating characteristics of machine screws are: overall size, shape of head, slot type, length, material, and thread type. The two main drive types associated with machine screws are slotted (flat head) and Phillips.
D. The wheel and axle (steering wheel or screwdriver)
Combines a wheel with a central fixed axle which ensures that both must rotate together. A small force applied at the edge of the wheel is converted by rotation to a more powerful force at the smaller axle.
