Problem 5.4. A particle of mass 4 kg moves along the x-axis with a velocity v = 15t m/s, where t = 0 is the instant that the particle is at the origin. (a) at t=2s, what is the angular momentum of the particle about a point P located on the +y-axis, 6m from the origin. (b) what torque about P acts on the particle?
