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प्रश्न
Write scientific reasons.
The value of gravitational acceleration (g) decreases as we go deep inside the earth.
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उत्तर
- The acceleration due to gravity (g) on earth’s surface is given as g = `"GM"/"R"^2`. The value of g depends on the mass M of the earth and the radius R of the earth.
- As we go inside the earth, our distance from the centre of the earth decreases and no longer remains equal to the radius of the earth (R).
- Along with the distance, the part of the earth which contributes towards the gravitational force felt also decreases, decreasing the value of (M).
- Due to the combined result of a change in R and M, the value of g decreases as we go deep inside the earth.
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संबंधित प्रश्न
What do you mean by acceleration due to gravity?
What is the acceleration of free fall?
State whether the following statement is true or false :
A falling stone also attracts the earth.
What do you mean by the term free fall ?
The values of g at six distances A, B, C, D, E and F from the surface of the earth are found to be 3.08 m/s2, 9.23 m/s2, 0.57 m/s2, 7.34 m/s2, 0.30 m/s2 and 1.49 m/s2, respectively.
(a) Arrange these values of g according to the increasing distances from the surface of the earth (keeping the value of g nearest to the surface of the earth first)
(b) If the value of distance F be 10000 km from the surface of the earth, state whether this distance is deep . inside the earth or high up in the sky. Give reason for your answer.
Why does a sharp knife cut objects more effectively than a blunt knife ?
Explain why, a wide steel belt is provided over the wheels of an army tank.
For freely falling object we can write the Newton’s second equation of motion as …..
A metal ball of mass 5 kg falls from a height of 490 m. How much time it will take to reach the ground? (g = 9.8 m/s2)
The total energy of an object falling freely towards the ground ______.
A car is moving with a uniform velocity 30 ms-1. It is stopped in 2 s by applying a force of 1500 N through its brakes. Calculate the following values : The retardation produced in car.
Define the term acceleration due to gravity? Write its S.I. unit.
What is the acceleration due to gravity?
Right or wrong sentence:
The value of gravitational acceleration at the centre of earth is zero.
Right or wrong sentence.
Free fall of an object does not depend on the mass of the object.
Write the acceleration due to gravity value on the surface of Earth.
Distinguish between:
Universal gravitational constant – Gravitational acceleration of earth.
Read the given passage carefully and answer the questions.
| We know that the force of gravity due to the earth acts on each and every object. When we were holding the stone in our hand, the stone was experiencing this force, but it was balanced by a force that we were applying on it in the opposite direction. As a result, the stone remained at rest. Once we release the stone from our hands, the only force that acts on it is the gravitational force of the earth and the stone falls down under its influence. Whenever an object moves under the influence of the force of gravity alone, it is said to be falling freely. Thus the released stone is in a free fall. In free fall, the initial velocity of the object is zero and goes on increasing due to the acceleration due to the gravity of the earth. During free fall, the frictional force due to air opposes the motion of the object and a buoyant force also acts on the object. Thus, true free fall is possible only in a vacuum. |
- Complete the following statement by choosing the right option.
The stone held in the hand is stable because on it ......- two unbalanced forces are exerted.
- only the gravitational force of the earth is exerted.
- gravitational force of the earth is not exerted.
- two balanced forces are exerted.
- Why does free fall not happen on the earth?
- Why does the velocity of the object increase during the free fall?
- Which type of force exerts on the object during free fall?
- Why does free fall happen only in a vacuum?
