A three tiered birthday cake rests on a table. From bottom to top, the cake tiers weigh 17N, 12N, and 7N, respectively. What is the magnitude and direction of the normal force acting on the second tier?

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?

A20 cm long spring is attached to a wall. the spring stretches to a length of 22 cm when you pull on it with a force of 100 n. what is the spring constant

The power exerted by a muscle is the product of the force exerted and the velocity of contraction. the area of which of these shaded regions represents the power exerted while a weight is lifted at maximum speed?