Question

A convex mirror forms an image that is half the size of the object. Supose the distance between the image and the object is 20 cm and determine the radius of curvature of the mirror.

Answer 1

Answer:

Radius of curvature =20cm

So, focal length =10cm

We are given, ho/2=hi

so,ho=2hi

so,m=hi=ho

m=ho/2ho

so,m=−v/u

1/2=−v/u

so,u=−2v

By mirror formula, 

1/f=1/v+1/u

1/10=1/v−(−1/2v)

1/10=1/v+1/2v

so,1/10=2+1/2v

so,1/10=3/2v

so,2v=30

so,v=15cm

u=−2(v)=−30