Question

A frog is 80 cm in front of a lens whose focal length is +50 cm. Another lens of focal length +20 cm, is 100 cm behind the first lens. Where is the image of the frog located? Is it real or virtual?

Answer 1

image location is at 12.5 cm distance from another lens

and image is real

Step-by-step explanation:

given data

distance q = 80 cm

focal distance f = 50 cm

focal length f2 = 20 cm

distance = 100 cm

to find out

image of the frog located and Is it real or virtual

solution

we apply here lens formula that is

1/f = 1/p + 1/ q

1/50 = 1/p + 1/80

p = 133.3 cm

so at another lens distance is 100 - 133.3

distance q = -33.3 cm

so lens formula

1/f = 1/p + 1/q

1/20 = -1/33.3 + 1/p

p = 12.5 cm

so image location is at 12.5 cm distance from another lens

and image is real