Question

An object is 3.6 m from the pinhole. Its image is 4.2 cm from the opposite side of the pinhole. The height of the image is 0.8 cm. What is the height of the object?

Answer 1

Height of the object is 68.6 cm.

Explanation:

The height of the object can be determined by:

`(object distance from pinhole)/(image distance from pinhole)` =
`(object height)/(image height)`

From the given question;

object distance from pinhole = 3.6 m = 360 cm

image distance from pinhole = 4.2 cm

height of image = 0.8 cm

So that;

`(360)/(4.2)` =
`(object height)/(0.8)`

⇒ object height =
`(360*0.8)/(4.2)`

=
`(288)/(4.2)`

= 68.571

object height = 68.6 cm

Thus, the height of the object is 68.6 cm.