Question

Which of the following statements about machines is true?

A)No machine exists with can magnify the strength of a force
B)A machine can never provide more output energy than it was provided with
C)Machine efficiency is found by checking its change in temperature
D)Machines are only ever complex mechanical structures

Answer 1

The true statement about machines is that a machine can never provide more output energy than the energy supplied to it because the energy in an isolated system is conserved, in accordance with the first law of thermodynamics.

Step-by-step explanation:

The true statement about machines from the options provided is that a machine can never provide more output energy than it was provided with. This concept is directly supported by the first law of thermodynamics, which states that energy cannot be created or destroyed in an isolated system. Hence, the efficiency of a machine will always be less than 100 percent because some energy is invariably lost as heat due to friction. Machines, such as levers, pulleys, and wedges, can multiply the force applied to them, but they cannot multiply energy. The mechanical advantage they provide means that while the input force can be made smaller, the distance over which the force is applied increases accordingly, keeping the work done (force times distance) constant.