The document defines velocity as the distance travelled per unit time in a given direction. Velocity is a vector quantity with both magnitude and direction. The velocity of a body can change by changing speed, direction, or both. Non-uniform velocity means the speed or direction changes over time. Average velocity is calculated as the total displacement divided by the total time. Several examples are provided to demonstrate calculating velocity using the formula velocity=displacement/time.

2.  Velocity of the body is the distance
travelled in a given direction per unit
time.
 In other words speed in a given direction
tells the velocity of the body.
 Velocity is the vector quantity having
both magnitude as well as direction.
 S.I unit of velocity is M/sec.

3. VELOCITY
V S
t
=
V=Velocity
S=Displacement
=Vector quantity
T=Time taken

5. The velocity of the body can be changed in any one of
the following 3 ways:-
 By changing speed of the body.
 By changing the direction of motion of the body.
 By changing both , speed and distance of motion.
Velocity of the body is said to be non-uniform when it
covers unequal distances in a particular directions on
equal interval of time or direction of motion of body
changes.

6. When velocity of the body is changing at the uniform
rate over the period of time then average velocity of the
body for this body is arithmetic mean of initial and
final velocity.
= initial velocity + final velocity
2
Vav =U + V
2
Vav= average velocity
U= initial velocity
V= final velocity

9. How fast will this ball move?
What factors may affect its
speed?

10. Rowing speed
= 16 km/hr
River speed
(downstream)
= 10 km/hr
Combined velocity: 26 km/hr
V1(Boat) = 16 km/hr
V2 (river) = 10 km/hr

11. What is the velocity if you are
moving upstream?
Combined velocity:
(V1) 16 km/hr – (V2) 10 km/hr =
(CV) 6 km/hr

13. 1. A tropical disturbance spotted east of
the Philippines was moving at 60 km per
hour at a Northwesterly direction and
having maximum sustained winds of 150
km/h? What is the storm’s velocity?
Given: S= 60km/h T= 10 sec dir.=
northwest
1. Formula= V= d/t with direction
2.Work/Answer= V= 60km/h Northwest

14. 2. A runner moving eastward covers a
distance of a 100 meters in 10 seconds.
What is his velocity?
Given: D= 100 m T= 10s dir.= East
1. Formula= V= d/t with dir.
2.Work= V= 100m/10s East
3.Answer= V= 10m/s East

15. 3. Lisa is walking to a friend’s house. She walks 500m for
10 minutes, then realizes she forgot something important
to bring. She turns around, and hurries back to her
house. The walk/jog back takes her 5 minutes.
Given: Total D= 500m + 500m = 1,000m
Total T= 10min + 5 min= 15 min
D= 500m
D= 500m
T= 10 min
T= 5 min

16. a. What was her average speed in m/min?
Given: Total Distance= 500m + 500m = 1,000m
Total Time= 10min + 5 min= 15min
1. FormulaAverage Speed = total D/total Time
2.Work= Average Speed = 1,000m/15min
3.Answer= Average Speed = 67 m/min

17. 4. Nelson is running around the track oval. The oval is
800m long. He is running at a constant speed. It takes
him 180 s to complete the track and get back to where
he started.
a. What is Nelson’s speed in m/s?
Given: d= 800 m t= 180 s running at constant speed

18. Given: d= 800 m t= 180 s running at constant speed
1. Formula= Velocity= d/t
2. Work= V= 800m/180 sec around oval
3. Answer= V= 4.44 m/s around oval
a. What is Nelson’s speed in m/s?
If Nelson is running at constant speed, is he also
moving at constant velocity ?
No, he is always changing direction
(running around the oval).

19. 5. Nemo is swimming his way to his best friend’s house
Crush (the turtle). Nemo is swimming at 12 km/h and
the current is moving at 10 km/hr.
a. On the way to Crush’s house, he
swims with the current. What is
Nemo’s combined velocity on
the way to Crush’s house?
Given: V1= 12km/h V2= 10 km/h direction= to Crush’s
house
(Nemo) (current)
1.Formula = Combined velocity= V1 + V2
2. Work= CV= 12 km/h + 10 km/h
3. Answer = CV= 22 km/h to Crush’s house
Current
Nem0

20. b. When Nemo leaves Crush’s to go home, he has to swim
against the current.
What is Nemo’s combined velocity
on the way home?
Given: V1= 12km/h V2= 10 km/h dir.= Nemo’s home
1.Formula = Combined velocity= V1 - V2
2. Work = CV= 12 km/h - 10 km/h
3. Answer = CV= 2 km/h on the way home
Against current