Showing posts with label work. Show all posts
Showing posts with label work. Show all posts

28 May 2009

classical physics jeopardy!

Classical Physics Jeopardy!!

Rules:
  • There are three teams of up to 8 students, as equal as possible. The teacher may weight teams so that the strongest students are in smaller groups. (If there are more than 24 students, there should be more teams so that there are never more than 8 in a group.)
  • The potpourri category does not have a 100-point question so that each team gets to choose the same number of questions. This works with 3 or 4 teams (and there shouldn't have to be more than 4 teams!)
  • A little different from "traditional" Jeopardy -- answers are not in the form of a question.
  • Each team elects a spokesperson at the beginning of the game. Only this person's answers count as the team's answer. A team loses 50 points every time the spokesperson does not confer with the group before answering, even if they were wrong! This is a group competition.
  • Each team in turn chooses a question and gets the first chance to answer it.
  • 100, 200, and 300-point questions: team has 30 seconds to conference before the spokesperson must answer or forfeit.
  • 400 and 500-point questions: team has 1 minute to conference before the spokesperson must answer or forfeit.
  • If the first team is incorrect, the next team in the sequence may answer for half points, and has half the conference time. If the second team is incorrect, this continues (further half points and half time) until all teams have had a chance.
  • Daily Doubles -- Team may wager points up to what they have or the question value (whichever is larger). If they are incorrect, the next team may answer for half the given point value (not a wager).
  • Final Jeopardy -- each team places a wager before the question is revealed. Each team has five minutes to solve the problem. Partial credit for each correct question: 0 correct = minus full wager, 1 correct = minus half the wager, 2 correct = plus half the wager, 3 correct = plus full wager.

Newton's Laws
  1. F = ma is the most common form of which of Newton's laws? (Second)
  2. A book pushes down on the table with 10 Newtons of force. With how much force does the table push back? (10 Newtons)
  3. (Daily Double) A large man and a small woman are standing on a bus that comes to a stop. The woman stumbles, and the man keeps his footing. Who has more inertia? (The woman, because she has less mass.)
  4. State Newton's Laws in sentence form. (1. An object in constant motion will remain in constant motion, and an object at rest will remain at rest, unless acted upon by an outside force. 2. A force acting upon a massive object will cause that object to accelerate. 3. For every force applied to an object, the object exerts an equal and opposite force.)
  5. A 1000-kg car is initially at rest. You push it with a constant force for 100 seconds, at which point it is traveling 5 m/s. What was your pushing force? (50 Newtons -- a = v/t = 5 m/s /100 s, f = ma = 1000 kg * 5/100 m/s/s.)
Vectors and Projectiles
  1. I walk one block north, then one block south. What is the magnitude and direction of the resultant vector? (Zero, which has no direction.)
  2. You throw a ball directly upwards, then catch it in your hand at the same height. It was in the air for a total of 8 seconds. At what time was the ball's velocity zero? (4 seconds after you threw it, at the point where it changed directions.)
  3. Does a projectile on Earth experience horizontal acceleration, vertical acceleration, both, or neither? If there is acceleration, what causes it? (Vertical acceleration only -- caused by gravity. Also OK: Both, since there may be horizontal drag forces.)
  4. Find the sum (magnitude and direction) of these vectors: 1 m/s up (0 degrees), 2 m/s to the right (90 degrees), and 3 m/s down (180 degrees). (Sqrt(8) m/s at 135 degrees.)
  5. A cannonball is shot at some angle on level ground. What equation should you use to find how long the cannonball is in the air, and why? Assume it is shot from ground level and neglect air resistance. (v_y(t) = 0 = -gt + v_oy -- solving for t tells you the time at which vertical velocity is zero, which is the top of the arc. Twice this is the total flight time.)

Energy and Electronics
  1. State the Work-Energy Theorem. (The work done on a system is equal to the total change in energy of the system.)
  2. What equation relates voltage, current, and resistance? (Ohm's Law, V=IR.)
  3. A 5-kg rock is held 10 m above the ground and dropped. How much kinetic energy does it have right before it hits the ground? Assume acceleration due to gravity is 10 m/s/s. (500 Joules -- KE = PE = mgh.)
  4. What is the total resistance when a 10-Ohm resistor is connected in parallel with two 5-Ohm resistors that are connected in series? (1/(1/10 Ohms + 1/(5+5) Ohms) = 5 Ohms.)
  5. (Daily Double) Describe how a generator in a hydroelectric dam produces an electric current. (The water turns a turbine, which turns a loop of wire in a magnetic field. This induces a current in the wire loop.)

Units
  1. What is the SI unit of acceleration? ( m/s/s )
  2. What is the SI unit of force, and what are its fundamental components? (Newton = kg*m/s^2)
  3. What is the SI unit of work, and what are its fundamental components? (Joule = N * m = kg*m^2/s^2)
  4. What is the SI unit of electric current, and what are its fundamental components? (Amp = coulomb/second)
  5. What is the difference between weight and mass? (Weight is a force, and mass is a fundamental quantity. Weight is measured in Newtons, and mass is measured in kilograms. An object can have different weights depending on the situation, but its mass does not change.)

Potpourri
  1. (Spare question) What is the gravitational acceleration at the surface of the earth, to one decimal place? (9.8 m/s/s)
  2. What is the name of the force that your chair is exerting on you? (The normal force.)
  3. How much force does a 1/10-kg apple exert while sitting stationary on Isaac's head? (1/10 kg * 10 m/s/s = 1 Newton.)
  4. What is the first step in the scientific process? (Create a hypothesis.)
  5. Name the four fundamental quantities and their SI units. (mass = kilograms, distance = meters, time = seconds, charge = coulombs)

Final Jeopardy
Category: Projectile motion

You are on the surface of Mars, where the gravitational acceleration is only 3.8 m/s/s. You get a running start and throw yourself into the air, with an initial velocity vector of 5 m/s at 30 degrees above horizontal. Neglect air resistance and presume the terrain is flat. 1. What is your velocity vector when you hit the ground again? 2. How long were you in the air? 3. How far did you jump?

1. 5 m/s at 30 degrees below horizontal (same as initial, but down).
2. 1.3 seconds
3. 5.6 meters

30 July 2007

general amusements

Hi everyone! Just a few things I felt like writing down.

I went fishing on Saturday with a family from church who "adopted" me -- their daughter Molly is Pete's age, and their son is my age but he's never around. We had a great time, and I caught three black crappies! They were all fairly large -- 8-12 inches, maybe. I have pictures, but I forgot to bring my camera in today so I'll post them later. This species is supposed to be really delicious, but we let them go after we took the pictures.

I biked to the mall yesterday, mostly for new jeans (which I found on sale at Old Navy, of course. Made in Cambodia, but they fit like a dream). Also got a pair of fingerless gloves from Hot Topic that say "good" on the fingers of one hand and "evil" on the other, but of course "good" is on the hand that hurts more! Typing is starting to be generally painful, so I'm taking frequent breaks (and Aleve).

JC Penney was having a sale yesterday, and somehow I got a cute t-shirt that was originally $14.99, marked down to $4.99, reduced to $4.19, and sold to me for only $2.99! Not sure exactly how that all worked, but I got me a new shirt for a sketchy-goodwill-shirt price! (it has pink and white stripes and a little lace at the collar -- adorable!)

Three days now until I leave for Melbourne and the second meeting, 10 until I go home. I'm giving a practice talk tomorrow, and on Wednesday I'm moving into my "guest apartment" for the remainder of my stay. It's sort of a hassle, but that's what I get for going to Lawrence.

That's all for now, I'll put up pictures when I remember.

02 July 2007

photometry

I guess I haven't posted anything since I finished what I was doing before.. I'm done removing noise from images (until the CD of new data from Dr. Perlman shows up), so now I'm finding the brightnesses of galaxies by comparing them to the stars around them in the images (aperture photometry). We expect the galaxies' brightnesses to vary with time, so I have to do this for every image we have since 2001, which takes a while, but isn't hard.

For some other objects, though, we don't know the magnitudes of the stars around the galaxy, so we have to do "Absolute Wide-Band Photometric Reduction", which Ken is working on because I have no idea how that goes.. it's considerably more complicated.

We had a public observing session on Saturday night because Venus and Saturn were less than a degree apart, but it was too cloudy to see anything. I did meet a family there, though, and I went to the Methodist Church with them on Sunday. I liked it a lot, and will probably go back next week. After church, they invited me for lunch and we had vegetable soup with ham.. it was delicious! They have a daughter in High School (Molly) who wants to be a physicist, and a son (Sean) who's my age (more or less). They decided they want to take me to see the attractions around here, namely the swamps and the beach in Jacksonville, so I'll probably be seeing them on several Saturdays in the coming weeks.

The Rumstays are leaving for the holiday to visit their oldest daughter, Roseanne, but I'm having dinner with them tomorrow night, and I think I'm going to bake a Key Lime Pie for that :) I got a recipe emailed to me from something or other I signed up for, and it looks like a good thing to do tonight. On the 4th, I might go see a movie .. Ocean's 13 if the major cinema is open, or 300 at the budget. Also I plan to sleep a lot :) And hopefully we'll get some rain soon!

14 June 2007

what i'm doing


here's a sweet screencap of what i did yesterday.. I think I'm learning something new today. We'll see.

Also, I started reading Surely You're Joking, Mr. Feynman!, which is hilarious!

13 June 2007

2007!

Hey everybody. Just finished for the day, which involves finishing all the preliminary processing on the images from 2007 -- hopefully I can finish 2006 before I leave for Kitt Peak on Saturday morning!

What I'm doing (so far) is essentially removing all the noise from the telescope images. There are 3 kinds of noise (two from the chip and one from everything else) that I have to take out using MIRA, which is tedious work, especially when there's 240 images of one thing!

That's about all for work... I met Dr Leake yesterday, and she's giving me a big trash can and a brush and dustpan that her student left last year. Dinner tonight will be rotini with spinach and fish, and maybe some carrots. Haven't decided yet if I want to put pasta sauce on that... maybe. It sounds good, but then I'd have to use all the sauce before I leave. And it's a lot of sauce.

Also, I just bought a (really!) cheap DVD player on eBay, since the computers in here don't have DVD drives and I have no other way to watch Batman Begins! But I have to buy the cables too.. eh. This won't be more than $20 total, which makes me happy. Works-great DVD player for $0.01, anyone? Yeah, I thought so. But shipping was $13.50. Whatever. Hopefully it'll work for 9 weeks.

Oh man, I'm hungry. Time to go make dinner!!