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प्रश्न
What do you mean by acceleration due to gravity?
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उत्तर
- When an object falls towards the ground from a height, then its velocity changes during the fall.
- This changing velocity produces acceleration in the object.
- This acceleration is known as acceleration due to gravity. Its value is given by 9.8 m/s2.
संबंधित प्रश्न
A stone is allowed to fall from the top of a tower 100 m high and at the same time another stone is projected vertically upwards from the ground with a velocity of 25 m/s. Calculate when and where the two stones will meet.
Explain why, if a stone held in our hand is released, it falls towards the earth.
Name the force which wears away two surfaces as they move over one another.
Solve the problem.
If the mass of a planet is eight times the mass of the Earth and its radius is twice the radius of the Earth, what will be the escape velocity for that planet?
A force causes an acceleration of 10 m s-2 in a body of mass 500 g. What acceleration will be caused by the same force in a body of mass 5 kg?
What force, in newton, your muscles need to apply to hold a mass of 5 kg in your hand? State the assumption.
Write scientific reasons.
The value of gravitational acceleration (g) decreases as we go deep inside the earth.
Define acceleration due to gravity.
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?
