JAMB - Physics (2001 - No. 6)
The efficiency of a machine is always less than 100% because the
work output is always greater than the work input
load lifted is always greater than the effort applied
effort applied is always greater than the load lifted
velocity ratio is always greater than the mechanical advantage
توضیح
In real-world machines, due to factors such as friction, deformation, and other losses, the mechanical advantage is always less than the velocity ratio:
MA < VR
This means that the work output (useful work done) is always less than the work input (energy supplied), leading to efficiency being less than 100%.