Unlike velocity, speed is scalar, which means it is described by__only.
a. direction
b. magnitude
c. time
d. motion

- Magnitude only

Unlike velocity, speed is scalar, which means it is described by magnitude only.

The correct answer is magnitude.

Explanation: A scalar quantity is a quantity that has magnitude only. For example distance, speed etc.

A vector quantity is a quantity that has magnitude as well as direction. For example displacement, velocity etc.

Velocity is a vector quantity and speed is a scalar quantity.

Suppose, a car is moving with 3 meter per second. It represents the speed at which the car is moving.

But car is moving with 3 meter per second in south direction. It represents the velocity because 3 meter per second is magnitude and south is a direction.

Therefore, Unlike velocity, speed is scalar, which means it is described by magnitude only.