Plz im lost

a 1-kg model airplane has 12.5 joules of kinetic energy and 98 joules of gravitational potential energy. what is its speed? what is its height?

Suppose a wheel with a tire mounted on it is rotating at the constant rate of 2.15 times a second. a tack is stuck in the tire at a distance of 0.373 m from the rotation axis. noting that for every rotation the tack travels one circumference (a) find the tack's tangential speed. (b) what is the tacks radial acceleration?