Q1. A meterstick is at rest in an inertial frame S2. If S2 moves with a speed of 0.7c with respect to a rest frame S1, find the length of the meterstick as measured in frame S1 according to classical physics. Reply in units of m.

Q2. Stationary bicycle is raised off the ground, and its front wheel (m = 1.3 kg) is rotating at an angular velocity of 12.0 rad/s (see the drawing). The front brake is then applied for 3.0 s, and the wheel slows down to 3.8 rad/s. supposes that all the mass of the wheel is concentrated in the rim, the radius of that is 0.31 m. The coefficient of kinetic friction between each brake pad and the rim is μk = 0.85. What is the magnitude of the normal force that each brake pad applies to the rim?