Ahypodermic needle consists of a plunger of circular cross-section that slides inside a hollow cylindrical syringe. when the plunger is pushed, the contents of the syringe are forced through a hollow needle (also of circular cross-section). if a 4.0-n force is applied to the plunger and the diameters of the plunger and the needle are 1.2 cm and 2.5 mm, respectively, what force, in n, is needed to prevent fluid flow at the needle?

the answer is b ) square root of 5

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