|
Lnk2Lrn™ 2010/11 - AP Physics B August 30 to September 8, 2010 Ch. 2: Kinematics in One Dimension. Galileo |
 |
Plans for the Week and Assignments:
1. Monday(08/30): Introduction to Mechanics, the study of motion.
Displacement, speed, velocity, and acceleration. HW: Read p.26-32,
then solve prob.4, 8, 12, and 16 on pages 49-50.
2. Tuesday(08/31): Applications of the Kinematics equations,
and freely falling bodies. HW: Read p.33-43, then solve prob.22, 28,
34, and 44 on pages 50-51.
3. Wednesday(09/01): Graphical Analysis of Motion. HW: Read
p.43-48, then solve prob.58, 60, and 61 on page 52.
4. Thursday(09/02): LAB experiment on Accelerated Motion.
HW: Process Lab data.
5. Friday(09/03): Post-Lab Discussion. HW: Complete lab
report and write Abstract (due Tuesday).
Monday(09/06): Labor Day - No School.
6. Tuesday(09/07): REVIEW for Test on Ch.2. HW: Complete
Handout.
7. Wednesday(09/08): TEST on Ch.2 - Kinematics in One
Dimension. HW: Go to web site for notes on Ch.3 - Kinematics in
Two Dimensions.
Very Important: If you have any questions or miss a class, see
me before school (8:00 - 8:30 AM), during Lunch, 7th hour, or after
school. Best to send an email to rpersin@fau.edu.
WEBSITE NOTES: Ch.2 - Kinematics in One-Dimension.
1. In Physics, the study of motion is known as Mechanics. This is divided
into Kinematics, the study of HOW things move, and Dynamics, which is
concerned with WHY they move.
2. Galileo (1564-1642) was the first to study motion and developed
Kinematics. He performed his experiments Pisa, Italy, frequently dropping
objects from the Leaning Tower and/or rolling spheres along level surfaces
and down ramps.
Isaac Newton (1642-1727), a theoretical physicist, formulated Dynamics by
deriving his 3 Laws of Motion and the Law of Universal Gravitation. We will
study his work in depth when we get to Chap. 4.
3. Galileo's study of motion produced four motion formulas: (I) Δx = vavg·Δt ,
with Δx = x - x0 , and vavg= (v0 + v)/2 , (II) v = v0 + a·Δt ,
(III) v2 = v02 + 2a·(x - x0) , and (IV) x - x0 = v0·t + ½a·(Δt)2 .
4. Instantaneous velocity can be computed by finding the slope of a tangent
line at any point on the graph of displacement as a function of time, or
v = Δx/Δt.
5. Instantaneous acceleration can be computed by finding the slope of a
tangent line at any point on the graph of velocity as a function of time, or
a = Δv/Δt.
6. Velocity and acceleration can also be evaluated using a much longer
method involving limits.
7. Keep in mind that we are still concerned with vectors. Displacement,
velocity, and acceleration are all directed quantities. In the previous
chapter we were also working with another vector, force.
8. Displacement, velocity, and acceleration can all be demonstrated
graphically. For example, straight lines on a position-time graph indicate
constant velocity, determined by the slope.
9. The area under a velocity-time graph is displacement while the slope
of the graph indicates acceleration. The area under an acceleration-time
graph is the velocity.
10. The acceleration due to gravity is -9.80 m/s2 for Earth at sea level.
The negative direction is downward.
11. This is known as free-fall acceleration and is the same for all
objects regardless of mass near the surface of the Earth.
12. To solve a motion problem in Physics use these steps:
(i) read the problem and identify the given variables
(ii) determine what you are asked to solve for
(iii) find the correct motion formula to use
(iv) use algebra to isolate the unknown
(v) substitute-in the given information and simplify.
Answers to the Homework:
Pages 49-50: #4 (9.1), #8(.81 km), #12 (8.18 m/s2), #16 ((a) North,
(b)7.1 m/s, South), #22 ((a) 1.6 m/s2, (b) 20 m), #28 ( v1 = 117 m/s,
v2 = 96.9 m/s)
Pages 50-51: #34 (1.7 s), #44 ((a) -7.9 m/s, (b) 3.2))
Pages 52: #58 (vA = -20 km/h, vB = 10 km/h, vC = 40 km/h),
#60 (vA = 6.3 km/h, vB = -3.8 km/h, vC = .63 km/h, vD = 0 km/h),
#61 (-8.3 km/h2)
Click HERE for detailed Homework Solutions.
|
|
ARCHIVES:
|
|
|
And Always Remember... "From Newtonian Mechanics, Through Quantum Theory, Without Physics, Life Would Be Dreary." |
IMPORTANT SITES TO VISIT: |
| LINK TO YOUR TEXTBOOK | |
| GALILEO | |
| KINEMATICS | |
| ACCELERATED MOTION | |