Give an example of each class of lever in a human body.

Complete the following sentences:

(a) Mechanical advantage = …………… × velocity ratio

(b) In class II lever, effort arm is …………… than the load arm.

(c) A pair of scissors is a …………… multiplier.

What is the purpose of a jack in lifting a car by it?

What do you understand by an ideal machine? How does it differ from a practical machine?