Draw diagrams to illustrate the positions of fulcrum, load and effort, in each of the following :

(a) a see-saw

(b) a beam balance

(c) a nut cracker

(d) a pair of forceps

The mechanical advantage of an actual pulley is less than 1. Give a reason. What is the justification for using the pulley then?

What is an inclined plane? What is its mechanical advantage? Give two examples where it is used.

Given below is a crossword puzzle based on this lesson. Read the clues across and clues downwards and fill up the blank squares.

Across:

1. It makes work easier …………… .
2. A …………… is a simple machine which is used for raising a load up by applying the effort downwards.
3. Work is said to be done when a …………… applied on a body moves it.

Down:

2. …………… force at the fulcrum reduces the mechanical advantage.
3. A …………… and axle is also a simple machine.
4. Screw driver is an example of wheel and …………… .
5. …………… is a rod which can turn about a fixed point (fulcrum)