the kinetic energy of an object of mass, m moving with a velocity city of 5ms-1 is 25 J. what will be its kinetic energy if its velocity is doubled?
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Expression for kinetic energy
Ek= ½ mv2
m = Mass of object
v = Velocity of the object in ms−1
Given that kinetic energy, Ek=25J
(i) If the velocity of an object is doubled, then v = 5 × 2 = 10 ms−1 . Therefore, its kinetic energy becomes 4 times its original value, because it is proportional to the square of the velocity.
Hence, kinetic energy = 25 × 4 = 100 J.
(ii) If velocity is increased three times, then its kinetic energy becomes 9 times its original value, because it is proportional to the square of the velocity. Hence, kinetic energy = 25 × 9 = 225 J.80
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first find mass of the object using 1/2 mv^2
then substitute mass to find the new kinetic energy
you get mass as 10
so new kinetic energy is 1/2 ×100×10
which is 500
then substitute mass to find the new kinetic energy
you get mass as 10
so new kinetic energy is 1/2 ×100×10
which is 500
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