What is the mechanical advantage of a pencil sharpener made from a wheel and axle with a mechanical advantage of 3 and a wedge with a mechanical advantage of 4?

3×4= 12

Explanation:

Mechanical Advantage( M.A.) in a simple machine is defined as the ratio of the force that performs the useful work of a machine to the force that is applied to the machine.

Mechanical Advantage of Compound Machine = Product of mechanical advantages of the simple machines that it consists of, that is the mechanical advantage of wheel and axle multipled by the mechanical advantage of wedge.

Therefore,

M.A. wheel and axle = 3

M.A. wedge= 4

M.A. pencil sharpener= 12

Note: Mechanical Advantage has no unit.