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प्रश्न
Write scientific reason.
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 combined result of a change in R and M, value of g decreases as we go deep inside the earth.
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संबंधित प्रश्न
What do you mean by free fall?
What do you mean by acceleration due to gravity?
Gravitational force acts on all objects in proportion to their masses. Why then, a heavy object does not fall faster than a light object?
Which force is responsible for the moon revolving round the earth ?
Fill in the following blank with suitable word :
The acceleration due to gravity on the moon is about ………………of that on the earth.
Explain what is meant by the equation :
`g= Gxxm/r^2`
where the symbols have their usual meanings.
What is the force of gravity on a body of mass 150 kg lying on the surface of the earth? (Mass of earth = 6 x 1024 kg; Radius of earth = 6.4 x 106 m; G = 6.7 x 10-11 Nm2/kg2)
What is the usual value of the acceleration due to gravity of earth ?
Name the force which pulled the apple off Isaac Newton’s tree.
An object thrown vertically upwards reaches a height of 500 m. What was its initial velocity? How long will the object take to come back to the earth? Assume g = 10 m/s2
For freely falling object we can write the Newton’s second equation of motion as …..
What would be the value of ‘g’ on the surface of the earth if its mass was twice and its radius half of what it is now?
A body falls freely under gravity from rest and reaches the ground in time t. Write the expression for the height fallen by the body.
What is the acceleration due to gravity?
What is escape velocity?
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Write scientific reason.
When we drop a feather and a stone at the same time from a height the stone reach the earth faster than a feather.
Write a short note.
Escape Velocity
The mass and weight of an object on earth are 5 kg and 49 N respectively. What will be their values on the moon? Assume that the acceleration due to gravity on the moon is 1/6th of that on the 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.
1) 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.
2) Why does free fall not happen on the earth?
3) Why does the velocity of the object increase during the free fall?
4) Which type of force exerts on the object during free fall?
5) Why does free fall happen only in a vacuum?
