Question

Answer of this question

Answer 1

tan 30° = 85/distance between lighthouse and boat
1/root 3 = 85/distance between lighthouse and boat
distance between lighthouse and boat = 85 root 3
now
tan 60° = 10/distance between lighthouse and boat
root 3 = 10/distance between lighthouse and boat
distance between lighthouse and boat=10/root 3
=10 root 3/3
distance between the boats from 30°- 60°

= 85 root 3 - 10 root 3/3
= 255 root 3/3 - 10 root 3/3
= 245 root 3/3
= 245 * 1.73/3
= 141.28 m or 141280 km
t = 2 min = 0.03

D = s * t
S = D /t
= 141280/0.03