plz help me in physics
posted by ahmed on .
A ship leaves the island of Guam and sails a distance 295km at an angle 35.0 north of west.
a:In which direction must it now head so that its resultant displacement will be 100km directly east of Guam? (Express your answer as an angle measured south of east)
b:How far must it sail so that its resultant displacement will be 100km directly east of Guam?
If it started at O (0,0), then after sailing NW, it arrives at P(-295 cos 35°, 295 sin 35°)
Now we want to arrive at point Q= (100,0)
SO, use the law of cosines to get the distance PQ: PQ² = 295² + 100² - 295*100*cos(180-35)
Now, use the law of sines to get the angle OPQ:
sin 145°/PQ = sin OPQ/100
Now, the heading is 55° + OPQ° east of south