A car of mass M traveling with velocity v strikes a car of mass M that is at rest. The two cars’ bodies mesh in the collision. The loss of t

Question

A car of mass M traveling with velocity v strikes a car of mass M that is at rest. The two cars’ bodies mesh in the collision. The loss of the kinetic energy the moving car undergo in the collision is

a) a quarter of the initial kinetic energy.
b) half of the initial kinetic energy.
c) all the initial kinetic energy.
d) zero.

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Phúc Điền 4 years 2021-07-22T03:17:30+00:00 1 Answers 48 views 0

Answers ( )

  1. dangkhoa
    0
    2021-07-22T03:19:06+00:00
    Reply

    Answer:

    the correct answer is B

    Explanation:

    Let’s propose the solution of the problem, for this we form a system formed by the two cars, so that the forces during the collision are internal, the momentum is conserved

    instantly starts. Before the crash

             p₀ = M v +0

    final instant. After the crash

            m_f = (M + M) v_f

    the moment is preserved

            p₀ = p_f

            M v = 2 M v_f

            v_f = v / 2

    let’s look for kinetic energy

    before the crash

           K₀ = ½ M v²

    after the crash

           K_f = ½ 2M (v_f)²

           K_f = ½ 2M (v/2)²

           K_f = (½ M v²) ½

           K_f = K₀ / 2

    therefore the correct answer is B

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