Question

A machine which is 75% efficient uses
12 J of energy in lifting up a 1 kg mass
through a certain distance. The mass
is then allowed to fall through, that
distance. The velocity of the ball at
the end of its fall is​

Answer 1

Answer:

given efficiency of the machine is 75% and it is spending 12 J of energy to lift that mass

according to the law of conservation of energy the stored potential energy in the mass will be converted to its kinetic energy. hence,

(12×75)/100=(m×v2)/2

v=$\sqrt{18}$ m/s