Science, asked by premshantikunj, 10 months ago

it is a screen at it is a point light sources o a ray incident on mirror perpendicularly and return back this mirror is some rotated through 22.5°this distance is 7 m then find the distance of image formed on screen from o​

Answers

Answered by simplystudent4
1

Answer:Suppose the number of revolutions are n. The angle between 2 positions of the rotating mirror =

2

1

×27degrees.

Since the angle of rotation of mirror is half the angle through which the reflected ray rotates.

The time taken by the mirror in rotating through an angle θ is given by t=

2πn

θ

=

2×180×n

13.5degrees

sec. -- Eqn 1

This is also the time taken by the light to travel from original point to the fixed mirror and back, thus

t=

c

2d

=

3×10

8

2×22500

[d=22.5km=22500mandc=3×10

8

m/s] -- Eqn 2

From eqns 1 and 2,

2×180×n

13.5

=

3×10

8

2×22500

or n =

2×180×2×22500

13.5×3×10

8

=

16200000

40.5×10

8

=

162×10

5

40500×10

5

=250revolutions/s.

Hence, the number of revolutions are 250 revolutions/s.

Explanation:

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