Question

ASSIGNMENT PHYSICS GRAVITATION
Class IX
What is the force of gravity betveen the earth and mass of 1 kg placed on its surface:
2 The value of g on the surface of the earth is 9.8 m/s". What will be its value on the surface of
tře moon?
3. A ball is dropped from a tower of height 5 m. With what velocity does it strike the ground? (g =
10 m/s)
4. A stone dropped from a tree takes 2 s to reach the ground. Find its velocity on striking the
ground
5. Mass of a book is 500 g on surface of the earth. What will be its mass at a height equal to
radius of earth?
6. What is meant by free fall? A ball is dropped from the roof of a building. It takes 10 seconds to
reach the ground. Find the height of the building. (g = 9.8 m/s?)
7. The earth attracts two objects A and B placed at same distance from its centre with same force.
Prove that their masses are equal.
8. Mass of a planet is twice that of the earth and its radius is four times of the earth. Find the
value of 'g on its surface
9. Find the force of gravitational attraction between the earth and a planet of mass M.
Me = 6 x 1024 kg, Mn = 1022 kg, Rem = 3.84 x 108m
10. If mass of the moon = 7.4 x 1022 kg, radius of the moon = 1.74 x 10°m, find the value of 'g' on
the surface of the moon.​

Answer 1

Answer:

on the moon its is 1/6th of acceleration due to gravity on earth i.e 1.68 m/s2 (approx)

2. 10 m/s final velocity

3. 20 m/s or 19.6 m/s

4. 1/2 kg of book should be at top i.e equal to 6378.1 km

5. Free fall can be defined as fall of body irrespective of mass in ideal case towards the earth from a hieght. it can be 500 m or 490 m

6. by applying newton's law of gravitation we get the answer

7. 3.1516 * 10^10

Explanation: