A 1200-kg car, C, traveling south at 25 m/s collides and locks with a 1800-kg car, D, traveling west at 30.0 m/s. At what speed do the cars move after the collision? Show your work.

Aperson stands on a platform, initially at rest, that can rotate freely without friction. the moment of inertia of the person plus the platform is ip. the person holds a spinning bicycle wheel with its axis horizontal. the wheel has moment of inertia iw and angular velocity ωw. take the ωw direction counterclockwise when viewed from above. part a what will be the angular velocity ωp of the platform if the person moves the axis of the wheel so that it points vertically upward?

Given the position vector of the particle r(t)=(t+1)i+(t^2−1)j+2t k, find the particle's velocity and acceleration vectors at t=1

When you push downward on a book at rest on a table, you feel an upward force. does this force depend on friction? defend your answer.