Question

Which of these is true about mechanical energy?

Mechanical energy is always conserved.

The mechanical energy of an object increases in free fall.

Mechanical energy sometimes changes into thermal energy.

Some of the mechanical energy in a system can simply disappear during an energy transformation.

Answer 1

@Psisquared

Answer 2

@IhteshamMalik

Answer 3

@shamim

Answer 4

i think conserved

Answer 5

mechanical energy sometimes changes into thermal energy