The royal gorge bridge in colorado rises 321 m above the arkansas river. suppose you kick a rock horizontally off the bridge. the magnitude of the rock's horizontal displacement is 45.0 m. find the speed at which the rock was kicked

When the force acting on an object points at least partially in the direction of the motion the work done is considered to be negative

Awind turbine is rotating counterclockwise at 0.5 rev/s and slows to a stop in 10 s. its blades are 20 m in length. (a) what is the angular acceleration of the turbine? (b) what is the centripetal acceleration of the tip of the blades at t=0s? (c) what is the magnitude and direction of the total linear acceleration of the tip of the blades at t=0s?

In a classical model of the hydrogen atom, the electron moves around the proton in a circular orbit of radius 0.053 nm. what is the electron's orbital frequency? what is the effective current of the electron?