In a Greek myth, Sisyphus is doomed for eternity, for cheating death twice, by Zeus to push a (100.0 kg) stone up a steep, 55.0° hill just to have it roll back down once he gets close to the top. If the coefficient of kinetic friction between the stone and the hill is 0.45, what is the acceleration of the stone back down the hill?

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?

Which diagram correctly demonstrates the various forces acting on a ball moving horizontally with some speed?

The coefficient of friction is a number that represents the resistance to sliding between two in contact with one another.