Question

A running of man has half k.e than that of a body of half his mass . The man speed up by 1m/s and then he has the same k.e as the body .find their initial speed.

Answer 1

hope it will help you

Answer 2

Answer:

velocity of man is 2.4 and velocity of the boy is 4.8

Explanation:

assume that mass and velocity of the man is M and V respectively

similarly, assume that mass an velocity of the boy is m & v respectively

M/2  =   m (given)

K.E. of man/2  =  K.E. of boy

1/2*M*V^2  =  1/2*m*v^2

$V=v/2$ this is equation 1

1/2*M*(V+1)^2 = 1/2mv^2

$v  =   \sqrt{2}(V+1)$ this is equation 2

from equation 1 and equation 2

$V = \sqrt{2}(V+1)/2\\V=2.4\\\\\\2V=v \\v = 4.8$