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A ball of mass 10 kg is moving with a velocity of 10 m/s. It strikes another ball of mass 5 kg, which is moving in the same direction with a velocity of 4m/s. If the collision is elastic their velocities after collision will be respectively?
 

  • Option 1)

    12m/s, 6m/s 

  • Option 2)

    8 m/s, 10 m/s 

  • Option 3)

    6m/s, 12m/s 

  • Option 4)

    10m/s, 8m/s

 

Answers (1)

best_answer

As we discussed in concept

Net work done by all the forces give the change in kinetic energy -

W=\frac{1}{2}mv^{2}-\frac{1}{2}mv{_{0}}^{2}

W= k_{f}-k_{i}

- wherein

m=mass \: of\: the\: body

v_{0}= initial\: velocity

v= final\: velocity

 

 

 v_{1}=(\frac{m_{1}-m_{2}}{m_{1}+m_{2}})u_{1}+(\frac{2m_{2}}{m_{1}+m_{2}})u_{2}

v_{2}=(\frac{2m_{1}}{m_{1}+m_{2}})u_{1}+(\frac{m_{1}-m_{2}}{m_{1}+m_{2}})u_{2}

on putting the values

v_{1}=6m/sec

v_{2}=12m/sec


Option 1)

12m/s, 6m/s 

Option is incorrect

Option 2)

8 m/s, 10 m/s 

Option is incorrect

Option 3)

6m/s, 12m/s 

Option is correct

Option 4)

10m/s, 8m/s

Option is incorrect

Posted by

divya.saini

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