Question

A man is watching from the top of a tower, a boat speeding away from the tower. The angle of depression from the top of the tower to the boat is 60* when the boat is 80m from the tower. After 10 seconds, the angle of depression becomes 300. What is the speed of the boat? (Assume that the boat is running in still water).

Answer 1

Answer:

plz mark me as brainliest

Step-by-step explanation:

Let AB be the tower and C and D be the positions of the boat.

then∠ACB=45∘,∠ADB=30∘,AC=100m

Let=>AB=h =AB/AC=tan45=1

=>AB=AC=100m

and,AB/AD=tan30=1/√3

=>AD=AB∗3–√3=100√3m

=>CD=AD−AC=100√3−100

=>CD=100(√3−1)m

We Know Speed = Distance/Time

=>Speed=[100(√3−1)/10m/sec=7.32

Please note answer we need in Km/Hr =>Speed=7.32∗18/5Km/Hr

=>Speed=26.352 Km/Hr  ANS