# Three particles A, B and C, each of mass m, are connected to each other by three massless rigid rods to form a rigid, equilateral triangular body of side l. This body is placed on a horizontal frictionless table (x - y plane) and is hinged to it at the point A so that it can move without friction about the vertical axis through A (see figure). The body is set into rotational motion on the table about A with a constant angular velocity w. (a) Find the magnitude of the horizontal force exerted by the hinge on the body. (b) At time T, when the side BC is parallel to the x-axis, a force F is applied on B along BC (as shown). Obtain the x-component and the y-component of the force exerted by the hinge on the body, immediately after time T.

Chetan Mandayam Nayakar
312 Points
11 years ago

Dear Jay,

a)The hinge exerts horizontal cebtripetal force on the body. This force passes through A and the mid-point of BC.

In order to solve (b), you need to specify the time duration for which F is applied, or else specify, through some other means, the IMPULSE of F.

net force=2mw2lcos30=mw2l√3

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