Question

image formed by a mirror for an object placed in front of an of it is An erect and enlarged image
a) what type of mirror is it be if the focal length of the mirror is 10 centimetre what should be the range of the distance of the object from the mirror b) where and why do we generally use this type of mirror

Answer 1

Let us consider the simple pendulam makes an angular displacement θ as shown in figure. At this position the forces are weight of the bob of pendulam and Tension acting on the string as shown in figure. Let us resolve the weight mg, the gravitational force into two perpendicular components as shown in figure. one component mgcosθ is in the direction of tension T, that equalize the tension which is giving necessary centripetal force for circular motion. The other perpendicular component mgsinθ is the restoring force acting on the bob to bring to its equilibrium position.