(i) A boy uses a single fixed pulley to lift a load of 50 kgf to some height. Another boy uses a single movable pulley to lift the same load to the same height. Compare the effort applied by them. Give a reason to support your answer.
(ii) How does uniform circular motion differs from uniform linear motion?
(iii) Name the process used for producing electricity using nuclear energy.
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(i) From relation,
$\text{M.A.} = \frac{\text{L}}{\text{E}}$
we can say that M.A. and effort are inversely related.
Therefore, we get,
$\frac{\text{Single Fixed Pulley Effort}}{\text{Single Movable Pulley Effort}} = \frac{2}{1}$
The reason is that the mechanical advantage of a single movable pulley is 2 while that of a single fixed pulley is 1.
(ii) The difference between uniform circular motion and uniform linear motion is as follows:
| Uniform circular motion | Uniform linear motion |
|---|---|
| In a uniform circular motion the velocity is variable (although the speed is uniform), so it is an accelerated motion. | In uniform linear motion the speed and velocity are constant and acceleration is zero i.e., the uniform linear motion is an unaccelerated motion. |
(ii) Nuclear fission