Uni Vectors and Horizontal Motion Review

A vector A = 5 i + 12 j m. What is its magnitude?

• 12.0 m

• 13.0 m

• 17.0 m

• 7.0 m

Which of the following is the unit vector in the direction of B = 3 i - 4 j?

• (0.6 i - 0.8 j)

• (0.8 i - 0.6 j)

• (3 i - 4 j)

• (4 i + 3 j)

The unit vector along R = 8 i + 15 j is:

• (0.47 i + 0.88 j)

• (8 i + 15 j)

• (0.6 i + 0.8 j)

• (15 i + 8 j)

If C = 7 i - 24 j, what is the direction angle θ from the +x axis?

• 106.6°

• 73.4°

• 45.0°

• 120.0°

The vector D = 10 i + 0 j is:

• purely horizontal

• purely vertical

• inclined 45°

• zero vector

A unit vector u has components (0.707, 0.707). Its magnitude is:

• 0.5

• 1.0

• 1.4

• 2.0

The vector P = 6 i + 8 j. Its unit vector is:

• (0.6 i + 0.8 j)

• (0.8 i + 0.6 j)

• (0.75 i + 0.25 j)

• (0.25 i + 0.75 j)

A vector has a magnitude of 20 m and is directed 60° above the +x axis. Its unit vector is:

• A. (0.5 i + 0.866 j)

• B. (10 i + 17.32 j)

Which is NOT a unit vector?

• (1, 0)

• (0, 1)

• (0.5, 0.5)

• (√2/2, √2/2)

If u is a unit vector in the direction of v = -5 i + 12 j, then u is:

• (-0.3846 i + 0.9231 j)

• (0.3846 i - 0.9231 j)

• (5 i - 12 j)

• (-12 i + 5 j)