A body starting from rest moves with uniform acceleration until it attains a speed of 100m/s after 20 s. It maintained this speed for the next 30s and came to rest by  uniformly deceleration in 30s. (a.) Find its acceleration. (b)Draw the velocity-Time graph of the motion  (c)Using the information given by the graph calculate The average speed for the whole journey

The total distance travelled

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?