Question

The mass of a person is 65kg.how much should he run so that his kinetic energy is 812.5joule.

Answer 1

ke=812.5 J
mass =65 kg
ke=1/2×mv^2
812.5=1/2×65v^2
v^2=812.5×2/65
v^2=65
v=5

Answer 2

k.e.=1\2mv^2
therefore v=√k.e.×2\m
=√812.5×2\65
=5