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Tell me? - Kinematics - NEET

A particle has initial velocity (3\hat{i}+4\hat{j}) and has acceleration (0.4\hat{i}+0.3\hat{j}). It's speed after 10 s is:

  • Option 1)

    7 units 

  • Option 2)

    7\sqrt{2}\: units

  • Option 3)

    8.5 units 

  • Option 4)

    10 units 

 
Answers (2)
118 Views

As learnt in

1st equation or velocity time equation -

 

V=u+at

V = Final velocity

u = Initial velocity

A = acceleration

T = time

-

 

 \vec{v} = \vec{u}+\vec{a}t

\vec{v} = \left ( 3\hat{i}+4\vec{j} \right )+\left ( 0.4\hat{i}+0.3\hat{j} \right )\times 10

\vec{v} = 3\hat{i}+4\hat{j} + 4\hat{i}+3\hat{j}

\vec{v} = 7\hat{i}+7\hat{j}

\left | v \right |= \sqrt{49+49}= 7\sqrt{2}


Option 1)

7 units 

This option is incorrect

Option 2)

7\sqrt{2}\: units

This option is correct

Option 3)

8.5 units 

This option is incorrect

Option 4)

10 units 

This option is incorrect

As learnt in

1st equation or velocity time equation -

 

V=u+at

V = Final velocity

u = Initial velocity

A = acceleration

T = time

-

 

 \vec{v} = \vec{u}+\vec{a}t

\vec{v} = \left ( 3\hat{i}+4\vec{j} \right )+\left ( 0.4\hat{i}+0.3\hat{j} \right )\times 10

\vec{v} = 3\hat{i}+4\hat{j} + 4\hat{i}+3\hat{j}

\vec{v} = 7\hat{i}+7\hat{j}

\left | v \right |= \sqrt{49+49}= 7\sqrt{2}


Option 1)

7 units 

This option is incorrect

Option 2)

7\sqrt{2}\: units

This option is correct

Option 3)

8.5 units 

This option is incorrect

Option 4)

10 units 

This option is incorrect

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