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? 發問於 Science & MathematicsPhysics · 2 月前

Physic: I don't know how to do (b), (c), would you mind to teach me, thanks?

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2 個解答

相關度
  • NCS
    Lv 7
    2 月前
    最愛解答

    (a) the horizontal component of the normal force exerted by the track on the marble

    (b) tanΘ = F / mg → the horizontal and vertical components

    F = m*g*tanΘ = 0.020kg * 9.8m/s² * tan20º = 0.071 N

    (c) F = 0.071 N = mv²/r = 0.020kg * v² / 0.10m

    so v = 0.60 m/s or 60 cm/s

    and period T = 2πr / v = 2π*10cm / 60cm/s = 1.05 s

  • oubaas
    Lv 7
    2 月前

    a) centripetal force is provided by the centripetal acceleration ca = V^2/r

    b) centripetal force CF = m*ca = m*V^2/r = m*r*g*tan 20/r = 0.02*9.8*0.364 = 0.07 N

    c) speed V = √r*g*tan 20 = √0.364*9.806*0.1 = 0.60 m/sec

    c') period T = C/V = 6.2832*0.1/0.6 = 1.05 sec  

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