Question

a convex mirror used for tear view on an automobile has a redius of corveture 4.00 ms. if abus is located at 8.00 m from this mirror ,find the position and magnifisens of the image​

Answer 1

given :

R=3m

f=R/2=3/2=1.5m

u=5m

v=?

Mirror formula:

1/f=1/u+1/v

by sign conventions:

1/1.5=1/-5+1/v

1/v=1/1.5+1/5⇒6.5/7.5

v=7.5/6.5

=1.15m

∴The image is virtual seen at the back of mirror.

m=hi/ho=-v/u

-1.15/-5=0.23

∴Image is erect and diminished in size by a factor of 0.23

Answer 2

u = -8m.

R = 4m then f = R/2 = 4/2 = 2m

V = ?

Mirror formula ;

1/f = 1/u + 1/v

1/f - 1/u = 1/v

1/2 - ( -1/8) = 1/v

1/2+ 1/8 = 4/8 + 1/8 = 5/8

5/8 = 1/v

V = 8/5

m = -v/u , m = -8/5/8 = 8/5 (1/8) = 1/5 = 0.2

Magnification = + 0.2

Magnification is positive this means that the image is virtual and erect, and m is less than 1 so it is diminished.

Position : the image is formed behind the mirror.