Question

1. what is the primary difference between a vector and a scalar?

only scalars have a frame of reference.
only vectors have a direction.
only vectors have a magnitude.
only scalars have a direction.

Explanation:

A scalar is a quantity that has only magnitude (e.g., mass, temperature). A vector is a quantity that has both magnitude and direction (e.g., velocity, force). So the key difference is that only vectors have a direction.

Answer:

Only vectors have a direction.