What is the acceleration of free fall ?

>

>

Chapter 9 NCERT Class 9 Science SOLUTIONS

8. What is the acceleration of free fall ?

Question:

What is the acceleration of free fall ?

Answer:

Acceleration of free fall is 9.8 m/s².

More NCERT Questions

Download Free PDF

(All Q's of this Chapter solved)

question pointer

Define average power.

question pointer

A lamp consumes 1000 J of electrical energy in 10 s. What is its power?

question pointer

Define 1 watt of power.

question pointer

What is power?

question pointer

The kinetic energy of an object of mass, m moving with a velocity of 5 ms–1 is 25 J. What will be its kinetic energy when its velocity is doubled? What will be its kinetic energy when its velocity is increased three times?

question pointer

Write an expression for the kinetic energy of an object.

question pointer

What is the kinetic energy of an object?

question pointer

A pair of bullocks exerts a force of 140 N on a plough. The field being ploughed is 15 m long. How much work is done in ploughing the length of the field?

question pointer

Define 1 J of work.

question pointer

Write an expression for the work done when a force is acting on an object in the direction of its displace-ment.

question pointer

When do we say that work is done?

question pointer

The volume of a 500 g sealed packed is 350 cm3 will the packet float or sink in water if the density of water is 1 g cm–3 ? What will be the mass of the water displaced by this packet ?

question pointer

The volume of 50 g of a substance is 20 cm3. If the density of the water is 1 g cm–3 will the substance float or sink ?

question pointer

Why does a block of plastic released under water come up to the surface of water ?

question pointer

In what direction does the buoyant force on an object immersed in a liquid act ?

question pointer

A ball thrown up vertically returns to the thrower after 6s find. (a) the velocity with which it was thrown up. (b) the maximum height it reaches and (c) it's position after 4s.

question pointer

A stone is allowed to fall from the top of a tower 100m high and at the same time another stone is projected vertically when and where the two stones will meet.

question pointer

Calculate the force of gravitation between the earth and the sun, given that the mass of earth = 6 × 1024 kg. and of the sun = 2 × 1030 kg. The average distance between the two is 1.5 × 1011 m.

question pointer

A stone is thrown vertically upward with an initial velocity of 40 m/s. Taking g = 10 m/s2 find the maximum height reached by the stone. What is the net displacement and the total distance covered by the stone ?

question pointer

A stone is released from the top of a tower of height 19.6 m calculate it's final velocity just before touching the ground.

question pointer

A ball is thrown vertically upwards with a velocity of 49 m/s Calculate. (i) The maximum height to which it rises. (ii) The total time it takes to return to the surface of the earth.

question pointer

Gravitational force on the surface of the moon is only 1/6 as strong gravitational force on the earth. What is the weight in newtons of a 10 kg object on the moon and on the earth ?

question pointer

Why will a sheet of paper fall slower than one that is crumpled into a ball ?

question pointer

Amit buys few grams of gold at the poles as per the instruction of one of his friends. He hands over the same when he meets his friend at the equator will the friend agree with the weight of gold bought ? If not, why ? [Hint : The value of g is greater at the poles than at the equator]

question pointer

What do we call the gravitational force between the earth and an object.

question pointer

What is the importance of universal law of gravitation?

question pointer

What happens to the force between two objects, if (i) The mass of one object is doubled. (ii) The distance between the objects is doubled and tripled. (iii) The masses of both objects are doubled.

question pointer

If the moon attracts the earth, why does the earth not move towards the moon ?

question pointer

The earth and the moon are attracted to each other by gravitational force. Does the earth attract the moon with a force that is greater or smaller or the same as the force with which the moon attracts the earth ? Why ?

question pointer

What is the magnitude of the gravitational force between the earth and a 1 kg object on its surface? (mass of the earth is 6 × 1024 kg and radius of the earth is 6.4 × 106m).

question pointer

Gravitational force acts on all objects in proportion to their masses. Why then, a heavy object does not fall faster than a light object ?

question pointer

How does the force of gravitation between two objects change when the distance between then is reduced to half ?

question pointer

You have a bag of cotton and an iron bar, each indicating a mass of 100 kg when measured on a weighing machine. In reality, one is heavier than the other. Can you say which one is heavier and why?

question pointer

You find your mass to be 42 kg on a weighing machine. Is your mass more or less than 42 kg?

question pointer

Why does an object float or sink when placed on the surface of water?

question pointer

What do you mean by buoyancy?

question pointer

Why is it difficult to hold a school bag having a strap made of a thin and strong string?

question pointer

If the masses of two objects are almost equal then what will be the acceleration due to the force of gravitation ?

question pointer

What is the reason for the occurrence of tides in the oceans ?

question pointer

What do you mean by acceleration due to gravity?

question pointer

What do you mean by free fall?

question pointer

Write the formula to find the magnitude of the gravitational force between the earth and an object on the surface of the earth.

question pointer

State the universal law of gravitation.

© 2026, Agrawal Group of Publications All rights reserved.