Question

two velocity vectors of magnitude 20 km/h and 40 km/h are to be subtracted. Which of the following are not possible values for the answer:

a) 10 km/h
b) 20 km/h
c) 30 km/h
d) 40 km/h

Answer 1

resultant of two vectors is given by\[R=\sqrt{a ^{2}+b ^{2}+2ab \cos \theta }\]
where theta is the angle between them.As you can see minimum value comes out to be \[\left| a-b \right|\].Therefore 10 cannot be the magnitude of any resultant.

Answer 2

thanks dude!