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    Can someone please help me with this question. No matter how many times I try, I keep getting the wrong answer.

    Question:
    Three boxes in contact are being pushed along a system of rollers. The two outer boxes each have a mass of 140 kg and the middle box has a mass of 80 kg. The single pushing force is 220 N. By drawing suitable free-body force diagrams, calculate,

    (a) the acceleration of the boxes

    Apparently the answer is 0.61ms^-2

    and heres my working out:
    220/140 = 1.57ms^-2
    220/80 = 2.75ms^-2
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    (Original post by CookieHero)
    ^
    Consider the boxes as a single object with mass (140 + 140 + 80)kg, then try again
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    140+140+80=360

    220/360=0.61ms^-2
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    (Original post by CookieHero)
    Can someone please help me with this question. No matter how many times I try, I keep getting the wrong answer.

    Question:
    Three boxes in contact are being pushed along a system of rollers. The two outer boxes each have a mass of 140 kg and the middle box has a mass of 80 kg. The single pushing force is 220 N. By drawing suitable free-body force diagrams, calculate,

    (a) the acceleration of the boxes

    Apparently the answer is 0.61ms^-2

    and heres my working out:
    220/140 = 1.57ms^-2
    220/80 = 2.75ms^-2
    Total F/ Total m= a
    Total F= 220N
    Total m= 140 + 140 + 80
    220/320 = 0.61m/s^2
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    Thanks for the help guys
 
 
 
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