Friday’s post includes the translational concepts we have studied, as well as the rotational equivalents. If you were absent, be sure to check this page.
Today
Read and takes notes on Section 7.1; pages 189-192. Turn in your notes for credit.
Work on all odd-numbered problems on page 218-219, numbers 1-13. Show all your work, and show both the SAE (inches, miles, etc.) and metric values when presented with SAE values (OK to use your phone for conversions).
Complete all problems for homework.
Remember you can check the answers to the odd-numbered problem in the back of the book, or the scanned versions here.
In our next unit we will be studying rotational motion. So far, the motion we have been studying is translational–where object move from one place to another. In rotational motion, things go around in circles, but the system doesn’t move from one place to another.
Comparing translational and rotational motion.
Translational concept
Equation and symbol
Rotational Concept
Equation and symbol
Displacement
∆x
Angular displacement
∆Φ
Velocity
V=∆x/∆t
Angular velocity
ω = ∆Φ/∆t
Acceleration
a=∆v/∆t
Angular acceleration
α = ∆Ω/∆t
Mass
M
Moment of inertia
I = m ∙ r2
Force
F=m ∙ a
Torque
τ = r ∙ f = I ∙ α
Work
W=F ∙ d ∙ cos(θ)
Work
Power
P=F ∙ v
Power
P = τ ∙ ω
Kinetic energy
Kinetic energy
Greek letters used above
You need to be able to use the name for these Greek letters
a (option: c if you say there is a slight increase in the kid’s momentum away from the sled and a slight increase in the sled’s
c
a
b
c
b
a
c
b
c
b
d
T
T
F
T
a
a (both have the same momentum, but Speedy G has more kinetic energy, and it’s the energy that can break bones since energy can be lost, and this loss of energy is what damages the object it hits)
Honors students will need to take a photo of a physics phenomena and describe the physics principles demonstrated by the photo.
Due date
Photos and essays must be submitted electronically to your teacher by 11:59pm, Wednesday March 11th.
Grading
Emphasis is on the composition of your photo and the accuracy of your physics explanation. 60% of your grade will be based on how well your photo captures a physics phenomena, and 40% of your grade will based on the quality and accuracy of your essay.
Guidelines
Photos
Sample natural photo
There are two categories of photos. Your can decide which category you enter.
(1) Natural photos are those that involve everyday situations that may demonstrate a variety of physics concepts.
(2) Contrived photos are those that are set up to show a particular physics concept or related set of concepts.
Original photos may be cropped for better composition (as long as the final product is still an 8” x 10” or 8½” x 11” print). Minimal manipulation of digital images with the intention of accurately rendering the subject is acceptable e.g.: small adjustments to brightness, color, color balance and/or sharpness, is acceptable. This is not a contest to see how well you can manipulate photos; emphasis is on the composition of your photo and the accuracy of your physics explanation.
All photos must be taken with a digital camera, and the original image must be emailed to your teacher. In order to avoid plagiarism, you must also submit an additional photo ‘selfie’ showing you in the photo (take this right before or after you take your contest photo).
