Question

a ball having mass 40microgram.
and its Kinetic energy is 0.4J.
calculate the velocity with which ball will move?

Answer 1

kinetic energy=1/2mv^2
0.4=1/2×40×10^-6×v^2
v=√2×10^2

Answer 2

$K.E. = \frac{1}{2} mv^2$
$v^2= \frac{2*K.E.}{m}$
$v= \sqrt{\frac{2*K.E.}{m}}$
$v= \sqrt{\frac{2*0.4*1000000}{40}}$
v = 141.4m/s