Advertisements
Advertisements
प्रश्न
For the same kinetic energy of a body, what should be the change in its velocity if its mass is increased nine times?
Advertisements
उत्तर
Let initial mass m1 = m, initial velocity v1 = v
Final mass m2 = 4m, Find velocity = v2
For the same kinetic energy,
`1/2`m1v12 = `1/2` m2v22 or `1/2` mv2 =`1/2` × 9m × v22
v2 =`sqrt(1/9"v"^2)=1/3"v".`
संबंधित प्रश्न
Two toy-cars A and B of masses 500 g and 200 g respectively are moving with the same speed. Which of the two has the greater kinetic energy?
A body of mass m is moving with a velocity v. Write the expression for its kinetic energy.
Calculate the decrease in the kinetic energy of a moving body if its velocity reduces to half of the initial velocity.
What happens to the K.E. when
(i) the mass of the body is doubled at a constant velocity and
(ii) the velocity of the body is doubled at constant mass?
Give one example when:
Electric energy changes to potential energy.
Give one example when:
Kinetic energy to potential energy.
What is nuclear energy? Explain the principle of producing electricity using nuclear energy is a nuclear reactor.
A body of mass m falls from a height h1 to a height h2, above the ground (h1 > h2). What is the loss of potential energy?
In a hydroelectric power station, 1000 kg of water is allowed to drop through a height of 100 m in 1 sec. If the conversion of potential energy to electric energy is 60%. Calculate the power output. [Take: g = 10m/sec2]
Energy from various sources is considered to have been derived from the sun. Do you agree? Justify your answer.
