54. A man on the top of a vertical tower observes a car moving at a uniform speed coming directly towards it. If it takes 12 minutes for the angle of depression to change from 30° to 45. how soon after this, will the car reach the tower? Give your answer to the nearest second.
Answers
Answered by
2
Answer:
Let AB be the tower and C and D be the two position of the boat
Let AB = h, CD = x and AD = y
y
h
=
tan60
0
=
3
⇒
y=
3
h
x+y
h
=
tan30
0
=
3
1
⇒
x+
y=
3h
∴
x=
(x+y)−
y=
(
3
h−
3
h
)
=
3
2h
Now
3
2h
is covered in 10 min
∴
3
h
will be covered in
(10×
h
3
×
3
h
)
=
5min
hope it will help you mark as brainlist answer
Attachments:
Similar questions