• 072920 77839
  • info@smartachievers.in
Menu
Back
  • JEE ADVANCE
  • JEE MAIN
  • NEET
  • BITSAT
  • CBSE BOARD
  • UP BOARD
  • CUET
JEE ADVANCE
  • CLASS XI - XII
  • CRASH COURSE
CRASH COURSE
JEE MAIN
  • CLASS XI - XII
  • CRASH COURSE
CRASH COURSE
NEET
  • CLASS XI - XII
  • CRASH COURSE
BITSAT
  • CLASS XI - XII
CBSE BOARD
  • CLASS IX
  • CLASS X
  • CLASS XI
  • CLASS XII
  • CLASS VI
  • CLASS VII
  • CLASS VIII
UP BOARD
  • CLASS IX
  • CLASS X
  • CLASS XI
  • CLASS XII
CUET
  • CRASH COURSE
Courses


Solution


Q.

The law of reflection states that when a ray of light reflects off a surface, the angle of incidence is equal to the angle of reflection.

Ramesh places a mirror on level ground to determine the height of a pole. He stands at a certain distance so that he can see the top of the pole reflected in the mirror. Ramesh’s eye level is 1.5 m above the ground. The distances from the mirror to Ramesh and from the mirror to the pole are 1.8 m and 6 m, respectively.

Based on the above information, answer the following questions:

 

(iii) (b) Now, Ramesh moves back so that the distance between him and the pole is 13 m. He places the mirror between himself and the pole to see the reflection of the pole's top correctly. What is the distance between Ramesh and the mirror
1 3m  
2 4m  
3 5m  
4 2m  

Ans.

(1)

Let MD = x m

Then BM=(13-x)m

Now, since ΔABM ~ ΔCDM,ABCD=BMDM⇒51.5=13-xx51.5=13-xx⇒5015=13x-1⇒13x=1+103=133⇒13x=133⇒x=3 m

Thus, distance between mirror and Ramesh is 3 m.