# Evan's Space

## Wonders of Physics # Light – Two mirrors in parallel

The diagram below shows a object O placed at the middle of two parallel mirrors. Which of the following is not a possible position of image of O? Solutions: Option D

Based on the concept of characteristics of mirror image – Distance of object to mirror is equal to Distance of image to mirror.

Object O at the centre of two mirrors, based on the above characteristic, B and C are possible positions of image of O.

Consider A. Treating C as the object now and using the mirror on the left, distance of C to left mirror is equal to distance of A to left mirror.

Hence A is a possible position of image of O.

Consider D. Treating B as object and using the mirror on the right, distance of B to right mirror is not equal to distance of D to right mirror.

Hence D is not a possible position of image of O.

### 4 thoughts on “Light – Two mirrors in parallel”

1. A ticker- tape is moved through a ticker -timer for 5.0 seconds.If the timer is operating at 25 Hz;
a) How many dots would have been printed on the tape?
b) What kind of motion does the tape represent? Give reason

• If frequency is 25 Hz that means it’s period is 1/25 = 0.04s to make a dot on tape. So in 5.0 seconds it will make 5.0/0.04 = 125 dots

• But u won’t be able to know the motion unless u have information on the spacing between the dots. E.g. if all the 125 dots are equally spaced apart then it’s moving at constant speed

2. U can refer to the post on ticker tape
https://evantoh23.wordpress.com/tag/tickertapetimer/