Question

1. The efficiency of the machine is equal to the ratio of the
a. Useful work to the work input
c. work input to the total work done
b. Useful work to the work output
d. total work done to the useful work
2. Which type of energy is a form of mechanical energy?
a. Heat
b. sound
c. Kinetic energy
d. Electrical energy
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Answer 1

Answer:

1-c and 2-b . sound is mechanical energy