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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
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?
What is the acceleration of free fall?
State whether the following statement is true or false :
A falling stone also attracts the earth.
During a free fall, will heavier objects accelerate more than lighter ones ?
Give reason for the following :
The force of gravitation between two cricket balls is extremely small but that between a cricket ball and the earth is extremely large.
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.
Explain why, a wide steel belt is provided over the wheels of an army tank.
Explain why, the tip of a sewing needle is sharp.
A ball falls off a table and reaches the ground in 1 s. Assuming g=10 m/s2, calculate its speed on reaching the ground and the height of the table.
For freely falling object we can write the Newton’s second equation of motion as …..
The acceleration produced in a body by a force of given magnitude depends on
A force acts for 10 s on a stationary body of mass 100 kg, after which the force ceases to act. The body moves through a distance of 100 m in the next 5 s. Calculate : The acceleration produced by the force
Figure shows the velocity-time graph of a particle of mass 100 g moving in a straight line. Calculate the force acting on the particle.
(Hint : Acceleration = Slope of the v-t graph)
Define the term acceleration due to gravity? Write its S.I. unit.
What force, in newton, your muscles need to apply to hold a mass of 5 kg in your hand? State the assumption.
What is escape velocity?
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.
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?
