1What is a simple machine? Give two examples.
2How many types of simple machine are there on the basis of construction? Write one everyday example of each.
3Why are the screw and the wedge not counted as separate types of simple machine?
4What is mechanical advantage? Why does it have no unit?
5Define velocity ratio and write its two formulas. Why is the second formula also correct?
6On a lever, an effort of 400 N raises a load of 600 N. While the effort covers 30 cm, the load covers 15 cm. Find the mechanical advantage and the velocity ratio of the lever.
7Why does a simple machine need no fuel? Name four such tools used in household work.