Question 3
Figure Q3 shows a pair of shears being used to cut steel wires. This pair of shears
has a mechanism, in which the grips are pivoted at C, and the cutting jaws at B; the
cutting jaws are also hinged to the grips at D and E. In the figure, the grips are
squeezed to rotate with an angular velocity $\omega = 0.12$ rad s$^{-1}$, inducing the cutting jaw
BD to rotate about B and hence cut the wire.
(a) Calculate the angular velocity of the cutting jaw BD. (20 marks)
(b) What is the magnification of the cutting force in comparison with the case of
applying the same conditions to simple shears without such a mechanism, i.e., the
jaw and the grip are a solid piece with no hinge at C. (15 marks)