Question

A 50g man is walking at a speed of 4m/s. what is the kinetic energy of the walker?

Answer 1

We have: K.E. = 1/2 mv²
Here: m = 50 g = 0.05 Kg
v = 4 m/s

Substitute their values, 
K.E. = 1/2 * 0.05 * 4²
K.E. = 1/2 * 0.05 * 16
K.E. = 0.4 J

In short, Your Answer would be 0.4 Joules

Hope this helps!