Question

A 14 cm object is 20 cm from a concave lens that has a focal length of -10cm.

Answer 1

-6.7cm just took the time to put this answer down because its been helping me and its right so good luck

Answer 2

Answer:

Distance of the image = q = - 6.7 cm

Explanation:

As the lens is concave so, distance of image and focal length will be negative.

Focal length = f = -10 cm

Object distance =  p = 20 m

Height of object = h = 14 cm

Distance of image = q = ?

Using concave lens formula,

1/f = 1/p + 1/q    ………… (i)  

By putting values in equation (i)

1/f – 1/p = 1/q

(1/-10) – (1/20) = 1/q  

1/p = -3/20

p = -20/3  

p = -6.6666 = -6.7 cm