CLASS 8 FORCE AND PRESSURE REVISION

CLASS 8 

FORCE AND PRESSURE

REVISION

1.During dry weather, while combing hair, sometimes we experience
hair flying apart. The force responsible for this is
(a) force of gravity. (c) force of friction.

(b) electrostatic force. (d) magnetic force.

2.Two objects repel each other. This repulsion could be due to
(a) frictional force only
(b) electrostatic force only
(c) magnetic force only
(d) either a magnetic or an electrostatic force
3. Which one of the following forces is a contact force?
(a) force of gravity (c) magnetic force

(b) force of friction (d) electrostatic force

4.A ball of dough is rolled into a flat chapatti. Name the force
exerted to change the shape of the dough.

5. Where do we apply a force while walking?

6. During dry weather, clothes made of synthetic fibre often stick to
the skin. Which type of force is responsible for this phenomenon?
7. While sieving grains, small pieces fall down. Which force pulls
them down?
8. Does force of gravity act on dust particles?
9. A gas filled balloon moves up. Is the upward force acting on it
larger or smaller than the force of gravity?
10. Does the force of gravitation exist between two astronauts in
space?


SHORT ANSWER QUESTIONS
11.A chapati maker is a machine which converts balls of dough into

chapati’s. What effect of force comes into play in this process?
12.Fruits detached from a tree fall down due to force of gravity. We
know that a force arises due to interaction between two objects.
Name the objects interacting in this case.

13. A man is pushing a cart down a slope. Suddenly the cart starts

moving faster and he wants to slow it down. What should he do?