Do anybody know the first one thanks help ASAP thanks

Abearing is designed to a reduce friction b. support a load c.guide moving parts such as wheels, shafts and pivots d. all of the above

Sound is a disturbance that travels through a medium as a

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?