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प्रश्न
Define acceleration due to gravity.
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उत्तर
The acceleration produced in a body under the influence of the force of gravity alone is called acceleration due to gravity.
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संबंधित प्रश्न
A stone is released from the top of a tower of height 19.6 m. Calculate its final velocity just before touching the ground.
Fill in the following blank with suitable word :
The acceleration due to gravity on the moon is about ………………of that on the earth.
Why does a sharp knife cut objects more effectively than a blunt knife ?
A pressure of 10 Pa acts on an area of 3.0 m2. What is the force acting on the area ? What force will be exerted by the application of same pressure if the area is made one-third ?
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 ______.
Define the term acceleration due to gravity? Write its S.I. unit.
An object falling freely from rest reaches ground in 2 s. If acceleration due to gravity is 9.8 m s-2, then the velocity of object on reaching the ground will be
What is escape velocity?
State whether the below statement is True or False.
Neglecting air resistance, a body falling freely near the earth's surface has a constant acceleration.
The value of gravitational acceleration (g) is ________.
The value of gravitational acceleration at the centre of earth is zero.
Free fall of an object does not depend on the mass of the object.
Write scientific reason.
The value of gravitational acceleration (g) decreases as we go deep inside the earth.
The mass of planet ‘X” is four times that of the earth and its radius is double the radius of the earth. The escape velocity of a body from the earth is 11.2 × 103 m/s. Find the escape velocity of a body from the planet 'X’.
Write a short note.
Escape Velocity
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?
