Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • Medical
  • Can someone help me with this, - Work, energy and power - NEET

A body of mass 1 kg begins to move under the action of a time dependent force \text{\vec F} = \left( {2\text{t}\hat i + 3\text{t}^2 \hat j} \right)\text{N},where {\hat i} and {\hat j} are unit vectors along x and y axis. What power will be developed by the force at the time t?

  • Option 1)

    (2t2 + 3t3) W

  • Option 2)

    (2t2 + 4t4) W

  • Option 3)

    (2t3 + 3t4) W

  • Option 4)

    (2t3 + 3t5) W 

 

Answers (1)

best_answer

As we learnt in

Power if the force is constant -

P=frac{dw}{dt}= P= vec{F}cdot vec{v}

- wherein

vec{F} ightarrow force

vec{v} ightarrow velocity

 

 we know that

f=\frac{\vec{dp}}{dt}=m\frac{d\vec{v}}{dt}

2+{\hat{i}}+3t^{2}\hat{j}=m\frac{d\vec{v}}{dt}

=>\int_{0}^{\vec{v}}\vec{d}v=\int_{0}^{t}\left ( 2t\hat{i}+3t^{2}\hat{j} \right )dt

\therefore \vec{v}=t^{2}\hat{i}+t^{3}\hat{j}

\vec{P}=\vec{F}. \vec{V}

=\left ( 2t\hat{i}+3t^{2}\hat{j} \right ).\left ( t^{2}\hat{i}+t^{3}\hat{j} \right )

=\left ( 2t^{3}+3t^{5} \right )w


Option 1)

(2t2 + 3t3) W

Incorrect

Option 2)

(2t2 + 4t4) W

Incorrect

Option 3)

(2t3 + 3t4) W

Incorrect

Option 4)

(2t3 + 3t5) W 

Correct

Posted by

Plabita

View full answer

NEET 2024 Most scoring concepts

    Just Study 32% of the NEET syllabus and Score up to 100% marks

Similar Questions

Trending Articles/News

anam-khan

NEET UG 2024 application correction window closes today; editable details, fees
anam-khan

NEET UG 2024: MBBS aspirants continue to demand postponement due to Lok Sabha polls
anam-khan

NEET UG 2024 application correction facility ends tomorrow

Latest Question