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प्रश्न
What do you understand by the kinetic energy of a body?
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उत्तर
Kinetic energy is the energy that a body possesses because of its motion. It is directly proportional to the mass and the square of the velocity of the moving body.
K.E = `1/2 m v^2`
संबंधित प्रश्न
The kinetic energy of an object of mass m moving with a velocity of 5 m s−1 is 25 J. What will be its kinetic energy when its velocity is doubled? What will be its kinetic energy when its velocity is increased three times?
Kinetic energy = 1/2 × mass × ............
A car is moving with a speed of 15 km h-1 and another identical car is moving with a speed of 30 km h-1. Compare their kinetic energy.
The kinetic energy of a body is the energy by virtue of its ______.
Two bodies of equal masses are moving with uniform velocities v and 2v. Find the ratio of their kinetic energies.
A cannon ball of mass 500 g is fired with a speed of 15 m s-1. Find:
- its kinetic energy.
- its momentum.
A body of mass 60 kg has the momentum 3000 kg m s-1. Calculate:
- the kinetic energy.
- the speed of the body.
A body falls freely under gravity from rest. Name the kind of energy it will possess on reaching the ground.
Two bodies have masses in the ratio 5 : 1 and their kinetic energies are in the ratio 125 : 9. Calculate the ratio of their velocities.
How fast should a man of 50 kg run so that his kinetic energy be 625 J?
What is the kinetic energy of a body of mass 1 kg moving with a speed of 2 m/s?
Two objects having equal masses are moving with uniform velocities of 2 m/s and 6 m/s respectively. Calculate the ratio of their kinetic energies.
A bullet of mass 15 g has a speed of 400 m/s. What is its kinetic energy? If the bullet strikes a thick target and is brought to rest in 2 cm, calculate the average net force acting on the bullet. What happens to the kinetic energy originally in the bullet?
A car is accelerated on a levelled road and attains a speed of 4 times its initial speed. In this process, the kinetic energy of the car :
Which of the following does not posses the ability to do work not because of motion?
Find out the form of energy possessed by the following thing.
Water falls
When stored water falls down, potential energy of water is converted into ______.
A car of mass 120 kg is moving at a speed 18 km/h and it accelerates to attain a speed of 54 km/h in 5 seconds. Calculate:
- the work done by the engine.
- the power of the engine.
The kinetic energy of a given body depends on the ______.
A ball of mass 0.5 kg slows down from a speed of 10 m s−1 to that of 6 m s−1. Calculate the change in the kinetic energy of the ball.
