The braking system shown in the figure uses a belt to slow down a pulley rotating in the clockwise direction by the application of a force P. The belt wraps around the pulley over an angle Ξ± = 270 degrees. The coefficient of friction between the belt and the pulley is 0.3. The influence of centrifugal forces on the belt is negligible.
During braking, the ratio of the tensions T1 to T2 in the belt is equal to __________. (Rounded off to two decimal places)
Take Ο = 3.14.
In an ideal orthogonal cutting experiment (see figure), the cutting speed V is 1 m/s, the rake angle of the tool Ξ± = 5Β°, and the shear angle, π, is known to be 45Β°.
Applying the ideal orthogonal cutting model, consider two shear planes PQ and RS close to each other. As they approach the thin shear zone (shown as a thick line in the figure), plane RS gets sheared with respect to PQ (point R1 shears to R2, and S1 shears to S2).
Assuming that the perpendicular distance between PQ and RS is πΏ = 25 ΞΌm, what is the value of shear strain rate (in s-1 ) that the material undergoes at the shear zone?
