Question

1) You are riding a bike at a speed of 4.3 m/s. You apply the rear brakes and come to a stop in 4 seconds. The moment of inertia of the rear bike wheel is 0.15 kg.m', and its radius is 0.33 m. If the rear wheel is rolling without slipping, what was the average torque exerted on it during the 4 seconds that you applied the brakes? (7 points)

Answer 1

briver, Vo = 4.3 m/s , Vf=omls in t = us I = 0.15 kg-m2, R = 0.33m First we need to find ang. acceleration (2) use envation of motion - Shu vo = at a = Vo = 9.3m/s = 1.075 ml. ofcousse negative) But this is deceleration not acceleration so, ve sign not used. use, a = 8x = x= % - 1.075 ml = 3.26 rad/s² 0.33m Etus. Now use relation of Torque and ang. accelesation cus - = I& z = 0.15 kg-m² x 3.26 sad /s2 2 = 0.489 N-ml " k Aug. Tosque Ans