1. Topic 1-1
Linear Motion

2. Science
Defined:
Use of evidence to construct testable explanations and predictions of natural phenomena, as well as the knowledge generated through this process.
Simple terms:
Study of testable events and observations

3. Types of Experiments
Comparative: Where you are looking for similarities and/or differences under testable situations Descriptive: Describing the results of testable situations Experimental: Formulating a testable hypothesis and describing/explaining the outcome

4. Motion Things moving around us all the time
Easy to recognize but hard to define
Motion is relative
Truly depends on your point of reference
Sitting in your desk, are you in motion?

5. Rates Defined: Any quantity divided by time Speed:
Rate at which we cover a given distance
Velocity:
Speed with direction
Formula:
Speed = distance/time
V = d/t
Unit:
m/s

6. Speed Continued Instantaneous:
Speed at a given moment in time or over a short period of time
Looking at speedometer gives us our instantaneous speed
What Mr. DPS Officer pulls us over for
Average:
Total distance covered over total amount of time
What we are mainly concerned with
Does not show variations

7. Velocity Common Definition: Same as speed they are interchangeable
Physics Definition:
Speed with a given direction
Constant Velocity:
Speed and direction does not change
Changing Velocity:
Speed and/or direction changes
Formula is the same as speed

8. Sample Question 1
If you can travel 272 km in 2.25 hours; what is your average velocity?
d = 272 km
t = 2.25 hours
V = ?
V=d/t
V = 272 km/2.25 h
V = 121 km/h

9. Sample Question 2
A plane traveled for about 2.5 hours at a velocity of 1200 km/h. What distance did it travel?
t = 2.5 hours
v = km/h
d = ?
V = d/t
d= vt
d = km/h x 2.5 hours
d = 3000 km (with correct number of sig figs = 3.0 x 103 km)

10. Sample Question 3
A car is traveling at 100. m/s. How many hours will it take to cover a distance of 750. m?
v = 100. m/s
d = 750. m
t = ?
v = d/t
t = d/v
t = 750. m / 100. m/s
t = 7.50 s

11. Sample Question
In 5.0 Seconds a car increases its speed from 50 Km/h to 65 Km/h. At the same time a truck slams on its breaks to avoid the car and goes from 15 km/h to rest. Which undergoes the greater acceleration?
Vi car= 50 m/s
Vf car = 65 m/s
t = 5.0 s
Vi truck = 15 m/s
Vf truck = 0 m/s
a = (vf – vi)/t
acar= (65-50)/5.0
acar= 3.0 m/s2
a = (vf – vi)/t
atruck= (0-15)/5.0
atruck= -3.0 m/s2
They undergo the same acceleration, but in different directions.