Gravitation

Gravitation Worksheet-13

21. Name these forces :

(a) the upward push of water on a submerged object

(b) the force which wears away two surfaces as they move over one another

(c) the force which pulled the apple off Isaac Newton’s tree.

(d) the force which stops you falling through the floor.

22. A pressure of 10 Pa acts on an area of 3.0 m². What is the force acting on the area? What force will be exerted by the application of same pressure if the area is made one-third ?

Gravitation Worksheet-14

31. (a) What are fluids? Name two common fluids.

(b) State Archimedes’ principle.

32. A piece of steel has a volume of 12 cm², and a mass of 96 g. What is its density :

(i) in g/cm³?

(ii) in kg/m³?

33. An elephant weighting 40,000 N stands on one foot of area 1000 cm² whereas a girl weighing 400 N is standing on one heel of area 1 cm².

Which of the two, elephant or girl, exerts a larger force on the ground and by how much?

Gravitation Worksheet-15

1. A falling stone also attracts the earth.

2. The force of gravitation between two objects depends on the nature of medium between them.

3. The value of G on the moon is about one-sixth (1/6) of the value of G on the earth.

4. The acceleration due to gravity acting on a freely falling body is directly proportional to the mass of the body.

5. The weight of an object on the earth is about one-sixth of its weight on the moon.

6. The buoyant force depends on the nature of object immersed in the liquid.