Question

the kinetic energy of an object of m mass an moving with velocity 5 meter per second in 25 Joule what will be its kinetic energy when it velocity in the doubled

Answer 1

the formula for KE is 1/2mv^2
now when v is made 2v we get rv so KE becomes 4 times so KE is 100 joule

Answer 2

Hi there!

Expression for Kinetic Energy:

${E}_{k} \: = \: \frac{1}{2}m {v}^{2}$

Where,
m = Mass of the object
v = Velocity of the object = 5 m/s

Given that kinetic energy, $E_k$ = 25 J

$E_{k} \: a \: {v}^{2}$

(i) If the velocity of an object is doubled, then its kinetic energy becomes 4 times the 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 the original value, because it is proportional to the square of the velocity. Hence, kinetic energy = 25  × 9 = 225 J.

Cheers!