Question

I
Figure shows an overhead view of a corridor with a
plane mirror M mounted at one end. A burglar B
sneaks along the corridor directly towards the
centre of the mirror. If d = 2.0m, then the distance
of B from the mirror at which the security guard S
first see her in the mirror is
A)lm
B)2m
c)3m
d)none​


please answer for me

Answer 1

Answer: Correct Answer is option A) 1 m.

Explanation:

Kindly refer to the attached figure while referring to the answer.

    As per the image, Security personnel will be able to just see the burglar when it will be reflected from the edge of the Mirror.

    The angle of reflection will be 45° because a straight line drawn from S to the edge of the mirror will subtend an angle of 45°.

 

     Let the distance of Burglar B from the mirror when security guard S first sees her be x m.

As per the Law of reflection , we know

$\frac{x}{\frac{d}{2} }$ = Tan 45°

We know, Tan 45° = 1

∴x = $\frac{d}{2}$,      d = 2.0 m ( given in the question)

∴x = $\frac{2}{2}$ = 1.0 m

∴The distance  of B from the mirror at which the security guard S  first see her in the mirror is 1.0 m.

Answer 2

Thus the distance of mirror B from the second mirror is 1 m.

Explanation:

We are given that:

Distance of mirror A = 2.0 m

To Find: Distance of mirror B = ?

Solution:

Angle of reflection in this case is 45°

By the law of reflective we find

x / d / 2 = tan 45°

x = d / 2

x = 2/2 = 1 m

Thus the distance of mirror B from the second mirror is 1 m.