15 September 2012

Worksheets for Class-VIII SCIENCE TOPIC: Force and Pressure

Worksheets for Class-VIII SCIENCE TOPIC: Force and Pressure
1. Name the force used in removing iron scrap from a heap of mixed scrap.
2. When is the pressure on the ground more – when a man is lying or when a man is  standing? Explain.
3. You can fill a bucket from a downstairs tap quicker than from an upstairs tap. Why?
4. Why do mountaineers suffer from nose bleeding at high altitudes?
5. Trucks and buses have double tyres in the rear end. Why?
6. Why do deep-sea divers have to wear special suits before going for diving at the depths?
7. Why is it easier to hammer a sharp nail into the wood than a blunt one?
8. Why does a balloon stick to the wall after it is rubbed on polythene?
9. State the type of force acting in the following conditions-
(a) Lifting a school bag.
(b) Bullocks ploughing the field
(c) Attraction of paper bits towards a comb.
(d) Attraction of iron nails towards a magnet.
(e) Stopping a goal by a goalkeeper.
(f) Coming downwards of the object even when it is thrown upwards.
10.An elephant weighing 50,000 Newton stands on one foot of area 1000cm2 . What is the
Pressure exerted on the ground?
11.A drawing pin is pushed against a wooden table with a force of 10 N. Calculate pressure  exerted on the ground by the person, when he is standing.
12.Give reasons-
(a) Buildings have wide foundations.
(b) It is easier to hold a school bag with wide straps than the one with thin strings.
(c) A bottle gets crushed when all its air is removed.
13. (a) State the relation between pressure exerted and area of the surface.  
 (b) State and define the unit of pressure.
14. How is gravity different from gravitational force?
15. How much force should be applied on a100cm2  area using pressure of 25 Pascal?
16. Fill in the blanks
(a)  S.I unit of pressure is ____________.
(b) The amount or the strength of force is called its_______________.
(c) Pressure in solid depends upon ________________ and ____________.
(d)  Pressure in liquids depends upon _____________ and ______________.
(e)  Force generated by moving of non living materials is called  ______________.

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