Principle of a Machine

How is mechanical advantage related to velocity ratio for a practical machine?

The figure below shows the use of a lever.

1. State the principle of moments as applied to the above lever.
2. To which class of lever does it belong ? Give an example of this class of lever.
3. If FA = 10 cm, AB = 490 cm calculate:
   1. the mechanical advantage and
   2. the minimum effort required to lift the load (= 50 N).

How does ideal machine differ from a practical machine ?

Two identical marbles A and B are rolled down along Path 1 and Path 2 respectively.

Path 1 is frictionless and Path 2 is rough.

1. Which marble will surely reach the next peak?
2. Along which path/s the mechanical energy will be conserved?
3. Along which path/s is the law of conservation of energy obeyed?

A pair of scissors is used to cut a piece of a cloth by keeping it at a distance 8.0 cm from its rivet and applying an effort of 10 kgf by fingers at a distance 2.0 cm from the rivet.

1. Find:
   1. the mechanical advantage of scissors and
   2. the load offered by the cloth.
2. How does the pair of scissors act: as a force multiplier or as speed multiplier?

Shows a uniform metre scale of weight W supported on a fulcrum at the 60 cm mark by applying the effort E at the 90 cm mark.

1. State with reason whether the weight W of the scale is greater than, less than or equal to the effort E.
2. Find the mechanical advantage in an ideal case.

State the principle of an ideal machine.

How is mechanical advantage related to the velocity ratio for an ideal machine?