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Smile 發問於 科學及數學物理學 · 4 月前

Physics: I don't understand how to do a, b and c. Thanks?

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1 個解答

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  • SC147
    Lv 6
    4 月前
    最愛解答

    (a) magnitude of acceleration, a

    = - g cos 35°

    = - 9.8 cos 35°

    = - ‭8.028 ms⁻¹ (to 3 dec. pl)

    (b) Let greatest distance that can be travelled = s

    v²-u² = 2as

    0²-4² = 2(-‭8.028)s

    ∴ s = ‭0.997 m (to 3 dec. pl)

    (c) Let time for it to reach to the highest position = t

    v = u + at

    0 = 4 + (- ‭8.028) t

    t = ‭0.4983 s

    ∴ time for it to return to the original position

    = 2t = ‭0.9966‬ s = 1.00 s (to 2 dec. pl)

    (d) cannot send in 2 photos!

    May be, I will give you a displacement-time table (Comment column) later, so that you can plot the graph by yourself. Please wait a bit ...

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    • SC147
      Lv 6
      4 月前舉報

      (d) 你不要這部份, 但都給你參考/教崶 :-
      s = ut + ½at²s = 4t + ½ (- ‭8.028)t²s = - 4.014t²+4t So, the displacement-time graph is : s = - 4t² + 4t , which is a parabola with vertex at s = 0.997≒ 1|t | 0 0.2  0.4 0.5  0.6  0.8  1s| 0 0.64 0.96 1 0.96 0.64 0

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