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    How to do question 1?
    Thank you
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    First two parts...doing third now:

    (a) Steady speed therefore P=Fv=40000 W
    F = 40000/25 = 1600N

    (b) Resolve up the slope: P/v - mgsin(arcsin(1/10))- 1600 = 0
    Hence P/25 = 1600 + (9.8*800)/10
    P = 59600W

    Therefore extra power required = 19600W
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    (i)

    F=P/v = 40000/25 = 1600N

    (ii)

    F(g) = mg sin a = 800*9.81/10 = 784.8N

    => extra power = Fv = 784.8*25 = 19620 W

    (iii)

    F = 900 + 784.8 = 1684.8

    => a = F/m = 1684.8/800 = 2.106 m/s²

    v² = u²+2as => s = 25²/(2*2.106) = 148.4 m
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    Resultant force acting on car down the slope =

    mgsin(arcsin(1/10))+900 = (800*9.8)/10 + 900
    =1684N

    Acceleration up the slope = F/m = -1684/800 = -2.105 m/s^2

    V^2 = U^2 + 2as
    0 = 25^2 + 2*-2.105*s
    s= 148.46 m
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    (Original post by elpaw)
    (i)

    F=P/v = 40000/25 = 1600N

    (ii)

    F(g) = mg sin a = 800*9.81/10 = 784.8N

    => extra power = Fv = 784.8*25 = 19620 W

    (iii)

    F = 900 + 784.8 = 1684.8

    => a = F/m = 1292.4/800 = 2.106 m/s²

    v² = u²+2as => s = 25²/(2*2.106) = 70.45m
    Calculator error there...
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    (Original post by chrisbphd)
    Calculator error there...
    yeah, just fixed it.
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    Thank you very much
 
 
 

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