What is the frictional force that is acting on the crate

Amajor difference radio waves, visible light, and gamma rays is the of the photons, which results in different photon frequencies and wavelengths

Which statement correctly describes the interaction between magnetic poles? north and south poles attract each other. north and south poles repel each other. two north poles will attract each other. two south poles will attract each other.

How do the forces acting on a boat compare to the force acting on a plane ?