Vector facts & stats

Question 1

What two properties does a vector have?

Accepted Answer

Magnitude and direction. A vector has both a size, called magnitude, and a direction.

Question 2

Which of these is a vector quantity?

Accepted Answer

Velocity. Velocity includes direction; temperature, mass and time are scalars with size only.

Question 3

What is the magnitude of the vector (3, 4)?

Accepted Answer

5. By Pythagoras, the length is the square root of 3² + 4², which is 5.

Question 4

What is the dot product of two perpendicular vectors?

Accepted Answer

0. The dot product includes the cosine of the angle between vectors, and cos 90° is 0.

Question 5

In biology, a mosquito that spreads a disease between hosts is called what?

Accepted Answer

A vector. A disease vector is a living carrier, such as a mosquito or tick, that transmits a pathogen.

Question 6

The cross product of two 3D vectors produces what?

Accepted Answer

A vector perpendicular to both. The cross product gives a vector at right angles to both input vectors.

Question 7

What is the dot product of (1, 2) and (3, 4)?

Accepted Answer

11. Multiply matching parts and add them: 1×3 + 2×4 = 3 + 8 = 11.

The basics