1. IMSS - Physical Science Wednesday, July 27th
Review motion diagrams
Tape timers
Introduction to forces
Forces and motion activity

2. Motion Diagrams How do we represent motion in a static picture?
How might you describe the motion of this car?

3. Motion Diagrams Stationary Constant speed Speeding up Slowing down
2-D motion

4. Motion Diagrams
Particle Model - A simplifying model in which we treat the object as if all its mass were concentrated at a single point. This model helps us concentrate on the overall motion of the object.

5. Displacement How fast is the car going? x (m) 0 10 20 30 40
Very important sequence of abstractcation
How fast is the car going?

6. Speed
assume 1 second
intervals
x (m)

7. Velocity
assume 1 second
intervals
X (m)

8. Velocity Slope = rise over the runDt Dx
Slope = rise over the run
The velocity is constant and positive

9. Displacement & Velocity
Describe Jason’s drive to work
time in minutes since leaving home
distance from home in miles 25 20 15 10 5
slow through Hayward
fast on 580
slow through Livermore

10. Displacement & Velocity
Describe Jason’s drive to work 60 50 40 30 20 10
speed in mph
time in minutes since leaving home

11. Acceleration A falling object 1 2 3 intervals are 0.2 sec apart 41 2 3 4 5
intervals are 0.2 sec apart
distance (m)

12. Acceleration
What is the velocity?

13. Acceleration Acceleration – the rate of change of the velocity
Slope of the vs. t graph
Units: (m/s)/s = m/s2

14. Acceleration

15. Describing Motion

16. Ticker Tape Timers
time interval fixed

17. Motion of a falling object1 2 3 4 5
distance (m)
a = 9.7 m/s2

18. Forces ... is a push or pull. ... acts on an object.
... requires an agent.
... is a vector.
... is a contact force or a long-range force.

19. Forces Fg = m*g The mass of the earth attracts other
masses and gives rise to the gravitational
force.
Fg = m*g
A net force on an object will lead to motion.

20. Forces and Motion Quantify how forces are related to motion
Using the airtrack, motion sensor, and weights, design an experiment.
Predict what you think will happen and make observations.
Form a hypothesis and then collect data to test it.
Analyze data with tables and graphs to come to a conclusion.
Prepare a 2-3 minute report on your results.