Question

Kinetic energy of a body of mass "m" moving with velocity "V" is K.
If the mass is doubled and velocity becomes v/2, the new kinetic
energy will be
a)K/4
b)K/2
c)K/3
d)2K​

Answer 1

Answer:

b) K/2

Explanation:

we know kinetic energy K is given as,

K = 1/2 mv^2

now as the mass m becomes 2m

and velocity v becomes v/2

then new kinetic energy K° = 1/2 (2m) (v/2)^2

=>K° = ( m × v^2 )/4

=>K° = 1/2 × K

(As, K = 1/2 mv^2)

hence the new kinetic energy is K/2