Anonymous
Anonymous asked in Science & MathematicsPhysics · 9 years ago

please help. a student is running at constant velocity of +5.0m/s in an effort to catch a bus?

parked at a station. when he is 10.0 m away from the bus, the bus pulls away with a constant acceleration of + 1.2 m/s². how much time will it take the student to catch the bus if he keeps running with the same velocity?

solutions and answer please :)

thank you.

2 Answers

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  • Anonymous
    9 years ago
    Favorite Answer

    Velocity = +5 m/s

    Distance = 10 m

    Acceleration of Bus = +1.2 m/s²

    Let the student catch the bus after time 't'

    In time 't', the bus travels -->

    h = ut + 1/2at² = 0 + 1/2(1.2)(t²) = 0.6 t²

    In time t, the student travels -->

    distance = speed x time = 5t

    But,

    Total distance traveled by Boy = (Initial 10 meters) + (Additional Distance the bus travels)

    5t = 10 + 0.6t²

    t = 5 sec or 3.33 sec

    Well you have two values of time and it seems neither of them can be rejected in any ways.

    ======================================

  • heloo
    Lv 4
    9 years ago

    constant velocity for the student so 5 = d+10 / t

    for bus:

    s =d

    u=0

    v=

    a=1.2

    t

    d= 0.5 a t^2

    d=0.6 t^2

    sub back in

    0.6 t^2 +10 /t =5

    0.6t^2 +10 =5t

    3t^2 - 25t +50 = 0

    (3t - 10)(t - 5) = 0

    t = 5

    t=3.33

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