When a force acts on a body along some path, the work done is W=F*s, where W is the work done, F is the force that is doing the work on the body and s is the path. The force doing the work has to be in the same direction, or parallel, as the path. This is called positive work. If the force and the path are anti-parallel, the work is negative. So the relationship between work and force is W=F*s.
Concave Mirror is a mirror with a curved reflecting surface that is bulging inward. This is the opposite of Convex Mirror which has a bulging outward surface. Concave mirrors are also called converging mirrors. The concave mirror reflected the light inward to a single focal point. These are usually used in reflecting telescopes.
Explanation:
d frequency I learned it last year