Physics
The pulley system is used in a machine:
- for gain in energy
- as a force multiplier
- as a force multiplier and for a gain in energy
- none of these
Related Questions
The diagram below shows the use of a lever.
(a) State the principle of moments as applied to the above lever.
(b) To which class of lever does it belong? Give an example of this class of lever.
(c) If FA = 10 cm, AB = 490 cm,
calculate:
(i) the mechanical advantage, and
(ii) the minimum effort required to lift the load (= 50N).
A fire tongs has its arms 20 cm long. It is used to lift a coal of weight 1.5 kgf by applying an effort at a distance 15 cm from the fulcrum.
Find:
(i) the mechanical advantage of fire tongs and
(ii) the effort needed.
A single fixed pulley is used because it:
- has a mechanical advantage greater than 1
- has a velocity ratio less than 1
- gives 100% efficiency
- helps to apply the effort in a convenient direction.
The figure given below shows a fixed pulley used by a boy to lift a load of 200 N through a vertical height of 5 m in 10 s. The velocity ratio of the pulley is
- 0
- 1
- 2
- none
