rowing a boat away from a lighthouse 150 m high takes 2 minutes003chan

1.	rowing a boat away from a lighthouse 150 m high takes 2 minutes003change angle of elevation of the top of lighthouse from 45Â° to 30Â°. FindA mansurmounted bygle of elevation ofe flagstaff is do1.7321the speed of the boat. IUse v3
Answer» Let the hieght of lighthouse be ydistance of boat initially = 150mdistance of boat from one point to another = xthus According to question tan 60 = y / 150thus y = 150 root 3 tan 45 = y / x+1501 = y / x + 150Thus y = x + 150 150 root 3 = x + 150x = 150 (root3 - 1) thus in 2 min speed will beu = x/t = 75 (root3 -1)

rowing a boat away from a lighthouse 150 m high takes 2 minutes003change angle of elevation of the top of lighthouse from 45Â° to 30Â°. FindA mansurmounted bygle of elevation ofe flagstaff is do1.7321the speed of the boat. IUse v3

Answer»

Let the hieght of lighthouse be ydistance of boat initially = 150mdistance of boat from one point to another = xthus

According to question

tan 60 = y / 150thus y = 150 root 3

tan 45 = y / x+1501 = y / x + 150Thus

y = x + 150

150 root 3 = x + 150x = 150 (root3 - 1)

thus in 2 min speed will beu = x/t = 75 (root3 -1)