A 7.0-kg shell at rest explodes into two fragments, one with a mass of 2.0 kg and the other with a mass of 5.0 kg. If the heavier fragment g

Question

A 7.0-kg shell at rest explodes into two fragments, one with a mass of 2.0 kg and the other with a mass of 5.0 kg. If the heavier fragment gains 100 J of kinetic energy from the explosion, how much kinetic energy does the lighter one gain?

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Hồng Cúc 4 years 2021-08-12T06:46:10+00:00 1 Answers 35 views 0

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  1. Dau
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    2021-08-12T06:47:26+00:00
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    Answer:

    39.94m/s.

    Explanation:

    Kinetic energy is expressed as KE = 1/2 mv² where;

    m is the mass of the body

    v is the velocity of the body.

    For the heavier shell;

    m = 5kg

    KE gained = 100J

    Substituting this values into the formula above to get the velocity v;

    100 = 1/2 * 5 * v²

    5v² = 200

    v² = 200/5

    v² = 40

    v = √40

    v = 6.32 m/s

    Note that after the explosion, both body fragments will possess the same velocity.

    For the lighter shell;

    mass = 2.0kg and v = 6.32m/s

    KE of the lighter shell = 1/2 * 2 * 6.32²

    KE of the lighter shell = 6.32²

    KE of the lighter shell= 39.94m/s

    Hence, the lighter one gains a kinetic energy of 39.94m/s.

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