Tuesday, January 27, 2009

Conduction






















We have begun to investigate Heat Transfer. We began with conduction - the movement of heat energy through solids by molecules bumping into each other. We started off by learning how to safely light a match and then a candle. Proper safety precautions were reviewed and practiced. Our first experiment was called "Hot Chocolate." The students placed 5, small chocolate bits on an aluminum "bridge." They placed a candle under the middle of the bridge, lit it, and timed how long it took for the bits to show signs of melting.







We then did an experiment called. "Heat Race" where we investigated if different metals conduct heat at the same rate. We used brass, iron, and copper wires. We measured and marked 2 spots on the wires 5 cm apart and placed a chocolate bit on one of the spots. We placed the candle under the other spot 5cm away, lit the candle, and time how long it took for the chocolate bit to show signs of melting. We did 3 trails for each wire and recorded the information on a data chart. This experiment culminated with a formal, written lab report.







To review what we learned about conduction, we did two demonstrations. One was with thermal conductivity bars placed into hot water and the other was with a heat conductometer - a devise with 5 different metal spokes.







Monday, January 26, 2009

Bird of the Week - XX







This week's "Bird of the Week" is the White-throated sparrow. The White-throated sparrow breeds in northern New England and Canada. Here in Reading, we will most commonly see the White-throated sparrow in the spring and fall during migration and in the winter. The White-throated sparrow feeds primarily on the ground, scratching the leaf litter with it's feet, looking for seeds, small fruits, and insects. It is also a frequent visitor to backyard bird feeders.



It is a large sparrow with a white throat, yellow in the front of the eyes, and white and black stripes on it's head. It's song is a slow series of usually five clear whistles that changes pitch once, on either the second or third note, often described as "Old Sam Peabody, Peabody, Peabody" or "Oh Sweet Canada, Canad, Canada."



Click on this link to learn more about the White-troated sparrow and to hear it's song.



Friday, January 23, 2009

Bird of the Week Quiz #3


Can you identify this bird? It is one of our "Birds of the Week." E-mail me with the correct answer by Monday, and your name will be put into a pool of correct answers. There will be 2 winners. I will buy the winners a lunch time ice cream from the cafeteria. Good luck!
dwilliams@reading.k12.ma.us

Tuesday, January 20, 2009

Bird of the Week - XlX




This week's "Bird of the Week" is the Canada goose. The Canada goose is the most wide spread and common goose in North America. This large waterbird has a black head and a long, black neck with a white chinstrap. It's breast is a light tan to cream color with a brownish back and a white undertail. The sexes look alike. It's call is a loud "honk."



There are 11 subspecies of the Canada goose, varying widely in size, with some Canada geese weighing about 7 pounds and ranging almost up to 20 pounds. The Canada goose is a popular game bird, often targeted by hunters.



The sight of migrating Canada geese flying high in a "V" shape form in the fall is quite a sight. Over the past 60 years, there has evolved a fairly large, non-migratory population of Canada geese here in Massachusetts. Many of these birds have become a nuisance, fouling town commons, golf courses, playing fields, and water supplies.



Canada geese feed in flocks and are herbivorous. That means they eat a variety of plant species and parts, especially grasses, sedges, grain, and berries.
















Thursday, January 15, 2009

Bird of the Week Quiz #2



Can you identify this bird? It was one of our "Birds of the Week." E-mail me the correct answer by tomorrow, and you will be eligible to be one of the 2 winners of a lunch time ice cream.
dwilliams@reading.k12.ma.us


Photo taken from Bird Watchers Digest.com


Monday, January 12, 2009

Bird of the Week - XVlll







This week's "Bird of the Week" is the Red-bellied woodpecker. The Red-bellied woodpecker is a relative new-comer to our area. It is a great example of a bird expanding it's range northward. It is not considered migratory, but it is at the northern edge of it's range and may move farther south in very cold winters. Ten years ago, the Red-bellied woodpecker was very uncommon around here. Now, we see it more frequently at feeders and in the backyard. While it's belly is covered in a light, red wash, it is easier to spot by the red on the back and top of its head.



The Red-bellied woodpecker is a medium to large-sized woodpecker, approximately 9 inches long with a wingspan of about 13 - 17 inches. It has a red hood from the top of it's head to the back of it's neck. It's back is barred black and white.



It will glean (eat ) insects from the bark of trees as well as using it's long bill to probe for insects in dead wood. The Red-bellied woodpecker will store food in cracks and crevices of trees and fence posts.
Photos from All About Birds and Bird Watchers Digest.









Friday, January 9, 2009

Dry Ice!






















Today we worked with Dry Ice! Dry ice is frozen Carbon Dioxide. It's temperature is -109 degrees F! (-78.5 degrees C). Dry ice changes directly from a solid to a gas - sublimation - without going through the liquid state.

video
video

Wednesday, January 7, 2009

Bird of the Week Quiz number 1


Can you identify this bird? It is one of our "Birds of the Week." E-mail me with the correct answer by Friday, and your name will be put into a pool of correct answers. There will be 2 winners. I will buy the winners a lunch time ice cream from the cafeteria. Good luck!


Drying out - Learning About Evaporation
















In today's activity, we looked at several of the factors that effect evaporation. The students were given a piece of paper towel. Using the electronic balance scale, they massed the paper towel and recorded it's mass. They then measured and poured 25ml of water into a small beaker. Then they stuffed the paper towel into the beaker and got the paper towel soaking wet. They took it out and squeezed as much of the water out as possible. There challenge was then to see what group could dry out their paper towel enough so that the mass of it would be equal to, or less than, the original mass.





After the activity, we generated a list of 4 factors that influence how fast or slow evaporation occurs.



1. Heat - the more, the better.


2. Moving air - the more, the better.


3. Exposed surfaced area - the more, the better.


4. Humidity - the less, the better.





Monday, January 5, 2009

Bird of the Week - XVll







This week's "Bird of the Week" is the American goldfinch. The Am. goldfinch is a small, colorful, abundant songbird. American Goldfinch is frequently found in weedy fields where it eats the seeds of weeds, flowers, and other plants. It is a common visitor to backyard bird feeders where it will often appear in flocks.



The Goldfinch is a small bird, about 4 - 5 inches long, with a small, pink, pointed, conical bill. It's wings are dark with large, white wingbars. The body is bright yellow to a dull brown and it's tail is short and notched. The breeding male is a bright yellow with a black cap and wings.
The American Goldfinch is one of the latest nesting birds. It usually does not start until late June or early July, when most other songbirds are finishing with breeding. The late timing may be related to the availability of suitable nesting materials and seeds for feeding young.


This winter, Pine siskins have been appearing at thistle seed feeders long with the Am. goldfinches. They can be a challenge to tell apart.
Photos from All About Birds.