Question

The vector -B has a magnitude of 25 m and makes an angle of 30 degrees with the +x axis. Which is true about the vector B?

A. It has the same direction as, but has a magnitude of 25 m

B. It makes an angle of -30 degrees with the +x axis

C. It has a magnitude of 25 m

D. It has the opposite direction as B and a magnitude of -25 m.

Answer 1

The given figure shows the arrangement of vectors

-B is acting with a magnitude of 25 with
`30^0 to +X axis`

So vector B is along the opposite direction of vector -B

Statement A is wrong since the direction is opposite

Statement B is also wrong since it makes
`240^0 to +X axis`

Statement C is correct since it has 25 m magnitude

Statement D is wrong because vector's magnitude cannot be negative.

So option C is the correct answer.