Question

5. Give scientific reasons.

a. When an object falls freely to the

ground, its acceleration is uniform.

b. Even though the magnitudes of

action force and reaction force are

equal and their directions are

opposite, their effects do not get

cancelled.

c. It is easier to stop a tennis ball as

compared to a cricket ball, when

both are travelling with the same

velocity.

d. The velocity of an object at rest is

considered to be uniform.








Question Bank​

Answer 1

Answer:

The gravitational force is given as,

F=G

(R+h)

2

m

1

m

2

From the above equation, it is clear that,

F∝

(R+h)

2

1

Since, R>>h

So, the height can be neglected.

Thus, the gravity acting on a freely falling object is constant and therefore, the acceleration due to gravity is also constant.