A horizontal disk of radius 0.6 m rotates freely about a vertical axis through its center with an angular speed of 1.5 rad/s. The rotational inertia of the disk is 4×104 kg.m?. Two wads of wet putties having masses 0.02 kg and 0.05 kg drop vertically on the disk from above and stick to the disk as shown in the figure at the same time. 6. a) What is the rotational inertia of the disk + putties system? b) What is the angular speed of the disk immediately after the two putties stick to it?

1) Choose the three "bridge" equations between translational quantities and rotational quantities from the list below.   A. Δx = RΔθ   B. vt = Rat   C. at = Rα   D. at = R/α   E. ω = Rθ   F. vt = Rω 2) Match the following angular velocity              A.I, kg·m2     angular displacement        B.Δθ angular acceleration          C.½Iω2 moment of inertia              D.α tangential velocity              E.ΣΤ = Iα tangential acceleration      F.Iω = mvR centripetal acceleration      G.Rω arc length                         H.w rotational kinetic energy  I.RΔθ angular momentum            J.Rω2 Newton's 2nd Law of Rotation        K.Rα 3) For a body to be in static equilibrium, what two equations must be solved together?   A. mechanical energy = 0 and net force = 0   B. net torque = 0 and net work = 0   C. net force = 0 and net torque = 0   D. net work = 0 and net force = 0 4)From Newton's Law of Gravitation, the quantity…

A 10 kg wheel with a 0.4 meter radius is rotating at 4 rad/s. A 8 Nm torque is applied to the wheel. The rotational inertia of the wheel is 0.48 kgm2. The angular momentum of the wheel changes by 4 kg*m2/s. How long was the torque applied to the wheel.   - 8 s - 3 s - 4 s  - 0.5 s

A solid uniform spherical boulder travels down a hill. At the top of the hill the boulder is rolling with a horizontal speed of 5 m/s. The top half of the hill is rough, so that the boulder continues to roll without slipping. The bottom half of the hill and the valley is covered in smooth ice, so that there is no static friction between the boulder and the hill. How fast is the boulder moving when it gets to the bottom of the hill? What is its rotational speed in the valley if the boulder has a radius of 10 cm? Rough 50.0 m Smooth