WBJEE · Physics · Work Power Energy
A body of mass \(6 \mathrm{~kg}\) is acted upon by a force which causes a displacement in it given by \(x=\frac{t^2}{4}\) metre where \(t\) is the time in second. The work done by the force in 2 seconds is
- A \(12 \mathrm{~J}\)
- B 9J
- C \(6 \mathrm{~J}\)
- D \(3 \mathrm{~J}\)
Answer & Solution
Correct Answer
(D) \(3 \mathrm{~J}\)
Step-by-step Solution
Detailed explanation
\begin{aligned} & \text {Hints : } \mathrm{m}=6 \mathrm{~kg} \quad \mathrm{x}=\frac{\mathrm{t}^2}{4} \\ & \frac{\mathrm{dx}}{\mathrm{dt}}=\mathrm{v}=\frac{\mathrm{t}}{2} \quad \mathrm{v}(0)=0 ; \mathrm{v}(2)=\frac{2}{2}=1 \\ & \mathrm{~K}_{\mathrm{i}}=\frac{1}{2}…
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