Question

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

Answer 1

Answer:

angle PAB=30

after6sec

angle PAC=60degree,angle ADB=90degree

angleABD=anglePAB

angleABD=30degree

angleACD=anglePAC so angleACD=60degree

tan60 =AC/CD

AB=root3CD

tan30 =AD/BD

AD=BD/root3

root3CD=BD/root3

3CD=BD/root3

CD=BC+CD

CD=BC/2

time taken to cover BC=6sec

time taken to cover BC=6/2

time taken to coverCD=3sec