1. Acceleration
and
non-uniform motion

2. P-T Graph
P-T Graph

3. P(m)
t(s)
Changing velocities means it is NON-uniform motion - this means the object is accelerating. = ∆t ∆v a
m/s2
m/s /s OR

4. - + Positive (+) Moving to the right Straight line
Origin - +
P(m)
T(s)
P - T Graph
+ slope
Positive (+)
Straight line
Moderate slope
Moving to the right
Uniform (+) velocity
Slow velocity

5. - + Moving to the RIGHT Positive (+) Increasing (+) velocity
Origin - +
P(m)
T(s)
P - T Graph
+ ↑ slope
Positive (+)
Increasing slope
Moving to the RIGHT
Increasing (+) velocity
(+) Acceleration

6. - + Negative (-) Moving to the LEFT Increasing slope
Origin - + d2 d1
P - T Graph
P(m)
- ↑ slope
T(s)
Negative (-)
Increasing slope
Moving to the LEFT
Increasing (-) velocity
(-) Acceleration

7. - + Positive (+) Moving to the RIGHT Decreasing slope
Origin - + d1 d2
P - T Graph
P(m)
+ ↓ slope
T(s)
Positive (+)
Decreasing slope
Moving to the RIGHT
Decreasing (+) velocity
(-) Acceleration

8. - + Negative (-) Decreasing slope Moving to the LEFT
Origin - + d2 d1
P - T Graph
P(m)
- ↓ slope
T(s)
Negative (-)
Decreasing slope
Moving to the LEFT
Decreasing (-) velocity
(+) Acceleration

9. The Sign of Acceleration

10. Velocity and Acceleration have SAME sign:
object is SPEEDING UP
Velocity and Acceleration have OPPOSITE sign:
object is SLOWING DOWN

11. Acceleration is calculated as the change in velocity over the change in time.
Acceleration has units of distance/time/time such as m/s/s (m/s2)
Acceleration is a vector quantity.

12. Velocity
AND
Acceleration

13. Keywords
Average velocity
Instantaneous velocity

14. Instantaneous velocity is the velocity of an object at a specific instant in time.
Uniform motion - average velocity is the same as instantaneous velocity on a P-T graph.
POSITION (m)
TIME (s) 10 20 30 40 50 5 15 25 35 50
- 15
- 0
v =
17.5 25
- 0
- 7.5
v = 2 m/s [E]

15. To find velocity for a specific time, you must estimate by making a straight line at that point.
POSITION (m)
TIME (s) 10 20 30 40 50 5 15 25
Slope of this line gives instantaneous velocity for that specific time on the curve.

16. A P-T graph with a changing slope means motion with changing velocity (non-uniform / acceleration)
POSITION (m)
TIME (s) 10 20 30 40 50 5 15 25
v = + 2 m/s
v = + 5 m/s

17. The study of motion (Kinematics) involves:
Motion is described in words.
Motion is described with a (data) table of values.
Motion is described with a graph.
Motion is describe with equations.
The study of motion (Kinematics) involves:
Position, Velocity, Acceleration