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mayankdevnani Group Title

A body of mass 2 kg is thrown up vertically with a kinetic energy of 490 J.If the acceleration due to gravity is 9.8 m/s^2, the height at which the kinetic energy of the body becomes half of the original value is - a) 50 m b) 25 m c) 12.5 m d) 10 m

  • one year ago
  • one year ago

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  1. mayankdevnani Group Title
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    @Hero @hartnn @Chlorophyll @robtobey @sauravshakya @kropot72 @jiteshmeghwal9 @hba

    • one year ago
  2. mayankdevnani Group Title
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    @mathslover have a look:)

    • one year ago
  3. mathslover Group Title
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    First find the original value ... what you get?

    • one year ago
  4. mayankdevnani Group Title
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    original value????

    • one year ago
  5. mathslover Group Title
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    sorry i think it is given

    • one year ago
  6. sauravshakya Group Title
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    Potential energy of the body =mgh

    • one year ago
  7. sauravshakya Group Title
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    u know it?

    • one year ago
  8. mayankdevnani Group Title
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    ok!!

    • one year ago
  9. mayankdevnani Group Title
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    yaa

    • one year ago
  10. mathslover Group Title
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    490 J = KE (ORIGINAL)

    • one year ago
  11. mayankdevnani Group Title
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    yaa

    • one year ago
  12. mathslover Group Title
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    half of it will be 490 /2 J = 245 J , correct?

    • one year ago
  13. mayankdevnani Group Title
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    why you do the half the K.E @mathslover

    • one year ago
  14. mathslover Group Title
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    @mayankdevnani because we have to find the height when the new kinetic energy equals half of the original one. ...

    • one year ago
  15. mayankdevnani Group Title
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    @03225186213

    • one year ago
  16. mathslover Group Title
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    therefore the new kinetic energy must be equal to 245 Joules.

    • one year ago
  17. mayankdevnani Group Title
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    yaa

    • one year ago
  18. mayankdevnani Group Title
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    correct!!!

    • one year ago
  19. mathslover Group Title
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    therefore we have : 1/2 m v^2 = 245 J 1/2 m (u^2 + 2gh ) = 245 J 1/2 m (2gh) = 245 mgh = 245 J 2 kg * 9.8 * h = 245

    • one year ago
  20. mathslover Group Title
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    solve for h and you will get h = 12.5 m

    • one year ago
  21. mayankdevnani Group Title
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    1/2 m (u^2 + 2gh ) = 245 J ??????????????

    • one year ago
  22. mathslover Group Title
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    got it?

    • one year ago
  23. mayankdevnani Group Title
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    no!!!!

    • one year ago
  24. mayankdevnani Group Title
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    1/2 m (u^2 + 2gh ) = 245 J this line!!!

    • one year ago
  25. mathslover Group Title
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    since v^2 = u^2 + 2gh therefore..

    • one year ago
  26. mayankdevnani Group Title
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    ok

    • one year ago
  27. mayankdevnani Group Title
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    thnx.... i got it @mathslover

    • one year ago
  28. mathslover Group Title
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    good,...

    • one year ago
  29. mayankdevnani Group Title
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    let @03225186213 be answer.... plz wait

    • one year ago
  30. 03225186213 Group Title
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    1/2 mv^2=mgh 490/2=2 (-9.8)h h= -9.8 because it is moving against gravity

    • one year ago
  31. mathslover Group Title
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    @03225186213 same I thought BUT it is given in the quest. that g = 9.8 m/s^2

    • one year ago
  32. mayankdevnani Group Title
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    yaaa you are correct thnx @mathslover and @03225186213

    • one year ago
  33. 03225186213 Group Title
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    welcome

    • one year ago
  34. mayankdevnani Group Title
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    :)

    • one year ago
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