When a plane mirror is placed horizontally on a level ground at a distance of 60 metre from the foot of a tower. The top of the tower and its image in the mirror subtend at the eye an angle of 90o , the height of the tower is:

Question

When a plane mirror is placed horizontally on a level ground at a distance of 60 metre from the foot of a tower. The top of the tower and its image in the mirror subtend at the eye an angle of 90o , the height of the tower is: (A)  30 m  (B)  40 m  (C)  60 m  (D)  90 m

Tardigrade Admin · Accepted Answer

tan 45=(h/60) 1=(h/60) ∴ h=60m Height of tower is 60 m.

Q. When a plane mirror is placed horizontally on a level ground at a distance of 60 metre from the foot of a tower. The top of the tower and its image in the mirror subtend at the eye an angle of $90^{o}$ , the height of the tower is:

$30 m$

$40 m$

$60 m$

$90 m$

$tan 45 = \frac{h}{60}$
$1 = \frac{h}{60}$ $∴$ $h = 60 m$ Height of tower is 60 m.

Q. When a plane mirror is placed horizontally on a level ground at a distance of 60 metre from the foot of a tower. The top of the tower and its image in the mirror subtend at the eye an angle of 90o , the height of the tower is:

30m

40m

60m

90m