# Velocity

Written by Jerry Ratzlaff on . Posted in Classical Mechanics

Velocity ( $$v$$ ) (VEL) is the rate of change or displacement with time.  Velocity is a vector quantity having magnitude and direction. The scalar absolute value of magnitude of the velocity vector is the speed of the motion.

Speed ( $$u$$ ) is the rate of change or distance with time.  Speed is a scalar quantity having direction.

Speed is a scalar quantity having direction, some of these include area, density, energy, entropy, length, mass, power, pressure, temperature, volume, and work

Velocity is a vector quantity having magnitude and direction, some of these include acceleration, displacement, drag, force, lift, momentum, thrust, torque, and weight.

### Velocity Formula

$$\large{ v = \frac { d } { t } }$$

$$\large{ v = v_i + at }$$

Where:

$$\large{ v }$$ = velocity

$$\large{ a }$$ = acceleration

$$\large{ d }$$ = displacement

$$\large{ t }$$ = time

$$\large{ v_i }$$ = initial velocity

Solve for:

$$\large{ t = \frac { d } { v } }$$

$$\large{ v_i = v - at }$$