a block of mass m is pulled across a rough surface as shown above. The coefficient of friction between the block and the surface

the duration of a photographic flash is related to an rc time constant, which is 0.100 μs for a certain camera.

the order for strong to weak forces such as

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force

the fundamental forces are those forces that act between to objects or element to make interactions. there are four types of fundamental forces such as strong and weak nuclear forces (due to protons and electrons), electromagnetic force (due to the motion of electrons) and gravitational force (due to orbital movement of the planet). if these forces are arranged on the basis of their maximum strength then the order is

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force

that would be because of both gravity and friction. so     c