Velocity
Definition Of Velocity
The rate of change of position is known as Velocity
More About Velocity
Velocity is a vector quantity
Velocity is also defined as the distance per unit time, i.e if s is distance travelled in time t, then velocity v = s/t
m/sec, cm/sec, ft/sec, km/hr, mles/hr
The first derivative of position vector (s) with respect to time (t) is also known as velocity. i.e 
Video Examples: What is Velocity?
Examples of Velocity
If Ed covers a distance of 225 miles in 5 hrs, then Ed drives with a velocity of 
miles/sec.
Solved Example on Velocity
Ques: A submarine descends 240 ft in 12 seconds. What is the velocity of the submarine?
Choices:
A. 30 ft per second
B. - 30 ft per second
C. - 20 ft per second
D. 20 ft per second
Correct Answer = C
Solution:
Step 1: Velocity = Displacemet /Time
Step 2: Since the submarine is descending, displacement will be negative.
Step 3: So, velocity = - 240/12 [Substitute the values of displacement and time.]
Step 4: = - 20 [Divide.]
Step 5: So, the velocity of the submarine is - 20 ft per second.