Questions about Chapter 3: Vectors.

Question No: 1

Two vectors are given by: A = -3.0 i + 4.0 j and B = 4.0 j + 3.0 k, where i,j and k are the unit vectors in the positive x, y and z directions. Find the angle between the vectors A and B.

A. 68 degrees

B. 50 degrees

C. 39 degrees

D. 90 degrees

E. 0 degree

Question No: 2

Vectors a , b and c are shown in figure (1). The vector c is equal to

A. a - b

B. b + a

C. b - a

D. a cos(theta)

E. b cos(theta)

Question No: 3

Two vectors a and b have equal magnitudes of 10 units. They are oriented as shown in figure (2), and their vector sum is r. Find the magnitude of r and the angle theta the vector r makes with +x direction.

A. r = 13 units and theta=80 degrees

B. r = 20 units and theta=150 degrees

C. r = 33 units and theta=60 degrees

D. r = 20 units and theta=30 degrees

E. r = 10 units and theta=120 degrees