If B is added to C=4.8ˆi+4.3ˆj, the result is a vector in the positive direction of the y axis, with a magnitude equal to that of C. What is the magnitude of B?

1 Answer
Sep 13, 2017

The magnitude of B is =5.25

Explanation:

The magnitude of C is

C=4.8ˆi+4.3ˆj=4.82+4.32=6.44

The angle is θ=arctan(4.34.8)=41.86

Applying the cosine rule to the isoceles triangle,

B2=C2+C22C2cos(9041.86)

B2=2C2(1cos(9041.86))=27.6

B=27.6=5.25

The magnitude of B is =5.25