Question

1. A concave mirror has a focal length of 50 cm. If a ball is placed 100 cm in front of the mirror, what is the image position? *
a. 150 cm
b. 100 cm
c. 75 cm
d. 50 cm
2. A pen is placed 30 cm in front of a concave mirror. If the image is located 20 cm in front of the mirror, what is the focal length of the mirror? *
a. 50 cm
b. 12 cm
c. 10 cm
d. 24 cm
3. A candle is placed in front of a concave mirror with a focal length of 20 cm forms a real image that is 60 cm from the mirror. What is the object position
a. 80 cm
b. 50 cm
c. 15 cm
d.30 cm

Answer 1

ANSWER

1.b)100cm

2.b)12cm

3.d)30cm

Explanation:

1) f=-50 cm

u=-100

v=?

mirror formula:

1/f=1/v+1/u

-1/50=1/v -1/100

1/v=-1/50+1/100

1/v=1/100

v=100