16) The friction force degends on the surface the block is sliding (slippery or rough) and the normal force on the block which is the force of gravity. The image above shows a block pulled across a table. The spring scale which measures in Newtons, reads the force resisting the motion known as friction force. In the image above, what is true about the force of friction? A) friction force is equal to normal force (force of gravity) B) friction force is more than normal force (force of gravity) C) friction force is less than normal force (force of gravity) D) friction force and normal force (force of gravity) are not related​