1. MOTION IN ONE DIMENSION
Mechanics: The study of motion of objects and related concepts of force and energy
Kinematics: the description of how objects move
Dynamics: deals with force and how objects move.

2. We will start our investigations with translational motion in one dimension.
The moving object will be considered as a point like particle (point particle)
Coordinate axis
Finding its position relative to some reference point
Locating an object

3. Change in position: displacement

4. SI BASE QUANTITIES AND UNITS
Length meter m
Time second s
Mass kilogram kg
a graph
x plotted as a function of time.
A good way to describe motion:
For the displacement delta x = x2 – x1 = 10.0 m – 30.0 m, the displacement vector points to the left.

5. Average Velocity and Average Speed
Q: How fast the object moves?
Several quantities are associated with how fast.
One of them
Average velocity

6. Average speed is another quantity that can describe haw fast on object moves

7. Instantaneous Velocity
Q: How fast a object moves at an instant?

8. v is the rate at which a particle’s positron x is changing with time at a given instant.
v at an instant is the slope of the particle’s position-time curve.

10. ACCELERATION
Change in velocity
acceleration
Average acceleration
Instantaneous acceleration

13. If we combine it with the definition of v.

15. CONSTANT ACCELERATION
Constant Acceleration – a common case
vo – velocity at t=0
v – velocity at t *

16. same way v vo t as **
* and ** are called basic equations

17. Which quantities are in these equations?
x-xo, v, vo, a, t
On the other side each basic equation contains four of these
5th quantity - either given or an unknown
In a typical problem, three of these quantities are given and 4th is asked to find.
Note which quantity is given and which quantity is asked
Then, use basic equations to derive a new equation which contains these quantities
Two basic equations can be combined to give three other equations
Each involves a different missing quantity

18. Eliminating t
Eliminating a
Eliminating vo

19. Independent of the object’s mass
FALLING OBJECTS
Galileo postulated that all objects would fall with the same constant acceleration
like
Independent of the object’s mass

21. a=-g=-9.80 m/s2
g=9.80 m/s2
Same transformation for the other four equations

22. Exercise
A pitcher tosses a baseball up along y-axis with an initial speed of 12 m/s (a) How long does the ball take to reach its maximum height? (b) What is ball’s maximum height above its release point