KnowledgeBoat Logo

Physics

(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.

Machines

ICSE 2017

23 Likes

Answer

(i) From relation,

M.A.=LE\text{M.A.} = \dfrac{\text{L}}{\text{E}}

we can say that M.A. and effort are inversely related.

Therefore, we get,

Single Fixed Pulley EffortSingle Movable Pulley Effort=21\dfrac{\text{Single Fixed Pulley Effort}}{\text{Single Movable Pulley Effort}} = \dfrac{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 motionUniform 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

Answered By

5 Likes


Related Questions