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प्रश्न
The total energy of an object falling freely towards the ground ______.
विकल्प
decreases
remains unchanged
increases
increases in the beginning and then decreases
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उत्तर
The total energy of an object falling freely towards the ground remains unchanged.
Explanation:
In an object falling freely to the ground, as the object's distance from the ground decreases, so does the potential energy stored in the object; But the kinetic energy of a freely falling object increases as the velocity increases over time. Thus, the potential energy lost by an object in free fall is equal to the kinetic energy it gains, i.e. the total energy of the object remains constant.
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संबंधित प्रश्न
Gravitational force acts on all objects in proportion to their masses. Why then, a heavy object does not fall faster than a light object?
A stone is released from the top of a tower of height 19.6 m. Calculate its final velocity just before touching the ground.
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?
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.
State whether the following statement is true or false :
The acceleration due to gravity acting on a freely falling body is directly proportional to the mass of the body.
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`g= Gxxm/r^2`
where the symbols have their usual meanings.
What do you mean by the term free fall ?
During a free fall, will heavier objects accelerate more than lighter ones ?
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The free fall of an object is possible only in _______.
Write scientific reason.
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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.
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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?
Calculate the escape velocity on the surface of the moon given the mass and radius of the moon to be 7.34 × 1022 kg and 1.74 × 106 m respectively.
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