a concave shaving mirror is construction so that a man at a distance of 20cm from the mirror sees his image magnified 1.5 times what is the radius of curvature of the mirror?
3 answers
I connot do it....plz help me....
M=1.5, object distance(u)=20cm.using the formula M=v/u,1.5=v/20,v=20*1.5=30cm.Again,1/f=1/u+1/v. 1/f=1/20+1/30(find the LCM) 1/f=1/12,so,f=12cm. We were asked to find the radius of curvature which can be known using this formula f=r/2,r=2f=2*12=24cm.
Answer is 120 cm