Question

A straight highway leads to the foot of a tower. A man standing at the top of the tower observes a car at an angle of depression of 60°, which is approaching the foot of the
tower with a uniform speed. Six seconds later, the angle of depression of the car is found
to be 30°. Find the time taken by the car to reach the foot of the tower from this point.

Kisi insaan me intelligent naam ki cheez ho toh krdo answer -.-

sab alag answer de rhe h
nonsense !​

Answer 1

Answer:

This is the required answer..

Answer 2

Answer:

Let AB be the tower.

D is the initial and C is the final position of the car respectively.

Angles of depression are measured from A.

BC is the distance from the foot of the tower to the car.

According to question,

In right

Δ

A

B

C

,

tan

60

∘

=

A

B

B

C

⇒

√

3

=

A

B

B

C

⇒

B

C

=

A

B

√

3

Also,

In right

Δ

A

B

D

,

tan

30

∘

=

A

B

B

D

⇒

1

√

3

=

A

B

(

B

C

+

C

D

)

⇒

A

B

√

3

=

B

C

+

C

D

⇒

A

B

√

3

=

A

B

√

3

+

C

D

⇒

C

D

=

A

B

√

3

−

A

B

√

3

⇒

C

D

=

A

B

(

√

3

−

1

√

3

)

⇒

C

D

=

2

A

B

√

3

⇒

A

B

=

√

3

C

D

2

Substitute this AB value in BC

⇒

B

C

=

√

3

C

D

2

√

3

⇒

B

C

=

C

D

2

Here, the distance of BC is half of CD. Thus, the time taken is also half.

Time taken by car to travel distance

C

D

=

6

s

e

c

.

Time taken by car to travel

B

C

=

6

2

=

3

s

e

c

.

Hence,the time taken by car to reach the foot of the tower from the given point is

3

s

e

c