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A particle has an initial velocity 3\hat{i}+4\hat{j} and an acceleration of 0.4\hat{i}+0.3\hat{j}. Its speed after 10 s is

  • Option 1)

    10\: units

  • Option 2)

    7\sqrt{2}\: units

  • Option 3)

    7\: units

  • Option 4)

    8.5\: units

 

Answers (1)

  As we learnt in

1st equation or velocity time equation -

V=u+at

V = Final velocity

u = Initial velocity

A = acceleration

T = time

-

 

 

v=u+at

\vec{v}=\left ( 3i+4j \right ) +\left ( 0.4i+0.3j \right ) \times10

\vec{v}=\left ( 3+4 \right )i +\left ( 4+3 \right )j

\left | \vec{v} \right |=\sqrt{49+49}=\sqrt{98}

7\sqrt{2} unit


Option 1)

10\: units

Incorrect

Option 2)

7\sqrt{2}\: units

correct

Option 3)

7\: units

Incorrect

Option 4)

8.5\: units

Incorrect

Posted by

Sabhrant Ambastha

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