What is the coefficient of friction for a surface if it takes 175 n to move a 30 kg object at a constant velocity across a horizontal surface

Tall pacific coast redwood trees can reach heights of about 100 m. if air drag is negligibly small, how fast is a sequola cone moving when it reaches the ground f it dropped from the top of a 100 m tree?

Area around a charged object where the objects can exert a force on another charged objects is an electric

Four identical lab carts each have a mass of 200 kg. different masses are added to the carts and the velocities are measured. all carts move to the right.