A man weighing 80kg is standing on a trolley weighing 320kg. The trolley resting on smooth horizontal rails. If the man starts wal

Question

A man weighing 80kg is standing on a trolley weighing
320kg. The trolley resting on smooth horizontal rails. If
the man starts walking on the trolley along the rails with
a speed of 1ms”, then his displacement relative to the
ground after 4 second is
1) 4.8 m 2) 4 m 3) 3.2 m 4) 2.8 m​

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Thu Hương 5 years 2021-08-18T04:39:18+00:00 2 Answers 20 views 0

Answers ( )

  1. thaiduong
    0
    2021-08-18T04:40:36+00:00
    Reply

    Answer:

    Net displacement = 3.2 m

    Explanation:

    Given:

    Mass of man = 80 kg

    Mass of trolley = 320 kg

    Speed = 1 m/s

    Time = 4 sec

    Computation:

    Displacement by man = 1 m/s × 4 sec

    Displacement by man = 4 m

    Net ext force (trolley) = com at rest

    So,

    320 × X = 80(4 – X)

    32X = 32 – 8X

    40X = 32

    X = 0.8 m

    Net displacement = 4 m – 0.8 m

    Net displacement = 3.2 m

  2. Xavia
    0
    2021-08-18T04:40:42+00:00
    Reply

    Answer:

    3) 3.2 m

    Explanation:

    The computation of the displacement relative to the ground after 4 seconds is shown below:

    Let us assume the following

    Starting x coordinate is at the origin

    As it does not involve any external force so x coordinated would remain unchanged

    Now the separation between the man and the trolley is

    = 4 \times 1

    = 4 m

    And, we assume the displacement of man be x

    So, for trolley it would be (4 -x)

    Now we develop the equation which is

    80 \times x = 320 \times (4 - x)

    x = 16 – 4x

    Therefore x = 3.2 m

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