Hel plzz I'm confused If the acceleration due to gravity is 9.8 m/s^2 and you drop a rock off the top of a building. It takes 4.5 s to hit the ground. How tall is the building?​

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?

How to calculate voltage drop in a series circuit

Explain what will happen if decomposers were apsent from a forest ecoysystem.