A war-wolf or trebuchet is a device used duringthe...

A war-wolf or trebuchet is a device used duringthe Middle Ages to throw rocks at castles and now sometimes used tofling large vegetables and pianos as a sport. A simple trebuchet isshown in the figure. Model it as a stiff rod of negligible mass,3.40 m long, joining particles of mass59.0 kg and 0.120kg at its ends. It can turn on a frictionless, horizontal axleperpendicular to the rod and 13.0 cm fromthe large-mass particle. The rod is released from rest in ahorizontal orientation.
(a) Find the maximum speed that the0.120 kg object attains.

(b) Select the statements that are nottrue.

Answers ( 1 )

  1. tamara webb
    tamara webb
    The radius of larger mass circular path r1 = 0.13 m
    The radius of the smaller mass m2 is r2 = 3.40 m - 0.13 m = 3.27 m
    The initial kinetic and potential energies are zero.
    According to conservation of mechanical energy we have
               KEf + PEf = 0
               0.5(I1?2 +I2?2) + (m2gr2 -m1gr1) = 0    .........1
    The whole system looks like dumble so that we can write themoment of inertia as
           I1 =m1r21 and   I2 = m2r22
    Substituting in eq 1 and solving for ?, weget
                              ? = ? ( 2(I1 -I2) / ( I1r1 +I2r2) )
    Substitute values.
    m2 =59.0 kg
    m1= 0.120kg
    r1 = 0.13 m
    r2 = 3.27m

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