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A 1200 kg car travels at 25.0 m/s and collides head-on in a perfectly inelastic collision with a stationary 2400 kg truck. The kinetic energy lost in the collision is

  • Option 1)

    330,000 J

  • Option 2)

    250,000 J.

  • Option 3)

    125,000 J.

  • Option 4)

    95,000 J.

 

Answers (1)

As we discussed in concept

Perfectly Inelastic Collision -

v= \frac{m_{1}v_{1}+m_{2}v_{2}}{m_{1}+m_{2}}

- wherein

Two bodies stick together after the collision ,so there will be a final common velocity (v)

m_{1},m_{2}= masses

v_{1}=\: initial \: velocity \: mass\: m_{1}

v_{2}=\: initial \: velocity \: mass\: m_{2}

 

 From conservation of Linear Momentum

m_{1}u_{1}+m_{2}u_{2}=(m_{1}+m_{2})v

1200\times 25+0 =(1200+2400)v^{'}

v^{'}\:=\:\frac{30000}{3600}=8.33

\therefore\:lost\:in\:K.E

\Delta K=\frac{1}{2}mv^{2}-\frac{1}{2}mv'\:^{2}

After calculating, we get lost in kinetic energy as 250,000 J


Option 1)

330,000 J

This option is incorrect.

Option 2)

250,000 J.

This option is correct.

Option 3)

125,000 J.

This option is incorrect.

Option 4)

95,000 J.

This option is incorrect.

Posted by

Vakul

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