You place a light bulb 8 cm in front of a concave mirror. you then move a sheet of paper back and forth in front of the mirror. the image of the light bulb focuses on the paper when the paper is 12 cm in front of the mirror. what is the focal length of the mirror? show work too.

sorry - late reply...just stumbled across tis...hope u can still use it :)

By the mirror equation: 1/di + 1/do = 1/f

where di = distance to image = +12cm (+ for real image)

and do = distance to object = +8cm

Substitute and solve for f, the focal length

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