JEE Mains · Physics · STD 11 - Work,energy,power and collision
- JEE Mains 2024
- Hard
- MCQ
A body of mass \(2 \mathrm{~kg}\) begins to move under the action of a time dependent force given by \(\overrightarrow{\mathrm{F}}=\left(6 \mathrm{t} \hat{\mathrm{i}}+6 \mathrm{t}^2 \hat{\mathrm{j}}\right) \mathrm{N}\). The Power developed by the force at the time \(t\) is given by _______.
Pick an option to check your answer.
Answer & Solution
Correct Answer
(D) \(\left(9 t^3+6 t^5\right)\ W\)
Step-by-step Solution
Detailed explanation
\(\overrightarrow{\mathrm{F}}=\left(6 \mathrm{t} \hat{\mathrm{i}}+6 \mathrm{t}^2 \hat{\mathrm{j}}\right) \mathrm{N}\)
\(\overrightarrow{\mathrm{F}}=\mathrm{ma}=\left(6 \mathrm{t}+6 \mathrm{t}^2 \hat{\mathrm{j}}\right)\)
\(\overrightarrow{\mathrm{a}}=\frac{\overrightarrow{\mathrm{F}}}{\mathrm{m}}=\left(3 \mathrm{t}+3 \mathrm{t}^2 \hat{\mathrm{j}}\right)\)
\(\overrightarrow{\mathrm{v}}=\int_0^{\mathrm{t}} \overrightarrow{\mathrm{a}} d \mathrm{~d}=\frac{3 \mathrm{t}^2}{2} \hat{\mathrm{i}}+\mathrm{t}^3 \hat{\mathrm{j}}\)
\(\mathrm{P}=\overrightarrow{\mathrm{F}} \cdot \overrightarrow{\mathrm{v}}=\left(9 \mathrm{t}^3+6 \mathrm{t}^5\right) \mathrm{W}\)
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