ICSE Class 10 Physics 2013 Solved Paper

Question : 6 of 70

Marks: +1, -0

A force is applied on a body of mass

20 {\kg}

moving with a velocity of

40 {\ms}^{-1}

. The body attains a velocity of

50 {\ms}^{-1}

in 2 seconds. Calculate the work done by the body.

Solution:

\;\text " Force "\;\;=m \;{(v-u)}/{t}=\;\text " m.a. "\;

\;\text " Displacement "\;\;=\;{ (v^2-u^2) }/{2 a}

\;\text " Work done "\;\;=\;\text " Force "\; × \;\text " Displacement "\;

\;=\;\text " m.a. "\; \;{ (v^2-u^2) }/{2 a}

{\W}\;=\;{1}/{2} m (v^2-u^2)

{\W}\;=\;{1}/{2} × 20 × (50^2-40^2)

\;=\;{1}/{2} × 20 × 900

\;=9000 {\Joule} .

Go to Question:

Prev Question

Next Question