Physics
How is mechanical advantage related to the velocity ratio for
(i) an ideal machine,
(ii) a practical machine?
Answer
(i) For an ideal machine (free from friction etc.), work output is equal to the work input, so the efficiency is equal to 1 ( or 100% ) and the mechanical advantage is numerically equal to the velocity ratio. So,
For an ideal machine, M.A. = V.R.
(ii) In the case of a practical machine, the mechanical advantage is always less than its velocity ratio or the output work is always less than the input work as some of the input energy is lost due to the force of friction etc. So,
For a practical machine, M.A. < V.R.
Related Questions
(a) What do you understand by a simple machine?
(b) State the principle of an ideal machine.
Name a machine for each of the following use —
(a) to multiply the force,
(b) to change the point of application of force,
(c) to change the direction of force,
(d) to obtain the gain in speed.
A machine works as a
(i) force multiplier,
(ii) speed multiplier.
In each case state whether the velocity ratio is more than or less than 1.
How is mechanical advantage related to the velocity ratio for an actual machine? State whether the efficiency of such a machine is equal to 1, less than 1 or more than 1.