A 65kg boy and his 40kg sister, both wearing roller blades, face each other at
rest. The girl pushes the boy hard, sending him backwards with a velocity of
2.9m/s towards the west. Ignore friction. What is the minimum amount of
chemical energy is converted into mechanical energy in the girl’s muscles?

Question

A 65kg boy and his 40kg sister, both wearing roller blades, face each other at
rest. The girl pushes the boy hard, sending him backwards with a velocity of
2.9m/s towards the west. Ignore friction. What is the minimum amount of
chemical energy is converted into mechanical energy in the girl’s muscles?

anonymous · Answer

I have no problem with finding the velocity of the girl. I just want to check what's it meant by chemical energy in this situation. Is it Kinetic energy? do I find it by using KE = 0.5 (mass of girl)(velocity of girl)^2 ?