"the total angular momentum of an object changes when a net external force acts on the system." this statement is:
a)always true b) never true c) sometime true, it depends on the force's direction
d)sometime true, it depends on the force's point of application
i can cancel out b). i think the correct answer is a) it doesn't depend on the force's direction or point of application does it?

Aboat radioed a distress call to a coast guard station. at the time of the call, a vector a from the station to the boat had a magnitude of 45.0 km and was directed 15.0° east of north. a vector from the station to the point where the boat was later found is = 30.0 km, 15.0° north of east. what are the components of the vector from the point where the distress call was made to point where the boat was found? in other words, what are the components of vector c = b - a?