AP EAMCET Engineering 18 Sep 2020 Shift 2 Paper

Energy spent by the machine to raise the body of mass 10kg at certain height, is E=100J
Since, machine is only 70% efficient.
Hence, energy used by machine,
E′=70% of E
=‌

70

100

×100=70J
When body is released, then whole energy spent by machine is converted into kinetic energy on reaching the ground.
∴ Kinetic energy, K=E′=70J