Answer:

Explanation:
Given that,
Mass of cabinet, m = 45 kg
Two horizontal force of 25 newtons and 18 newtons respectively in the same direction.
When the forces are acting in same direction, the net force is equal to the sum of forces i.e.
F = 25 N + 18 N = 43 N
Let a is the aceleration of the cabinet
So,
F = ma

So, the acceleration of the cabinet is
.
The correct answer is
C. reduce the friction between its moving parts
In fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.
Actually it's

and it says that the energy of an object (E) is equal to the mass (m) of the object multiplied with the squared speed of light (

). This theory says that mass can be turned into energy and energy can be turned into mass. This is one of Einstein's theory of relativity.