Question

What is lever ? What is efficiency of lever? ​

Answer 1

Answer:

First- and second-class levers generally are very efficient, especially when the loads are located close to the fulcrum while efforts are further from the fulcrum . The efficiency of first- and second-class levers will decrease when loads move further from the fulcrum

Answer 2

Muscles and bones act together to form levers. A lever is a rigid rod (usually a length of bone) that turns about a pivot (usually a joint). Levers can be used so that a small force can move a much bigger force. This is called mechanical advantage.

There are four parts to a lever – lever arm, pivot, effort and load. In our bodies:

bones act as lever arms

joints act as pivots

muscles provide the effort forces to move loads

load forces are often the weights of the body parts that are moved or forces needed to lift, push or pull things outside our bodies.

Levers can also be used to magnify movement, for example, when kicking a ball, small contractions of leg muscles produce a much larger movement at the end of the leg.