A 77 kg girl and a 62 kg boy face each other on friction free roller skates. The girl pushes the boy, who moves away at a speed of 2.5 m/s. What is the girl's speed? ​

Respuesta :

Answer:

Explanation:

conservation of momentum

Initial momentum is zero

77v + 62(2.5) = 0

77v = -155

   v = -155/77 = -2.0129870...

 |v| = 2.0 m/s