Investigating Temperature in Insulators
Preliminary Investigation
Question
Which of the four materials acts as the best insulator when wrapped
around a glass beaker which is filled with boiling water?
Aim
The aim of this investigation is to test four materials (polystyrene,
fibre glass, cotton wool and bubble wrap), to see which one acts as
the best insulator. The temperature of the boiling water and the
material inside and outside will be taken at regular intervals by a
data logger and form this it will show the material that can insulate
the best. So this chosen material can be further tested in the main
practical by testing various thicknesses of the material, finding the
optimum size at which the material acts best as the insulator.
Theory
In theory a good insulator and poor insulator will produce a graph
like this:
[IMAGE]A good insulator will keep the temperature of the boiling water
as high as possible during the 20 minutes it will be timed for. And so
will produce a steep curve like the one in blue on the graph, which
would represent a good insulator.
A poor insulator wont be able to keep the temperature in the water, or
insulate it well so the temperature will drop fairly quickly.
Prediction
I predict that cotton wool will be a good insulator because it will be
very good at reducing the heat loss. This is because inside cotton
wool there are many small pockets of trapped air, and air is a very
good insulator in small pockets. However I believe that fibre glass is
also a good conductor because this material also traps air, thus
preventing loss of heat due to convection currents. Air in its self
will also be a good insulator, but as I am only using the polystyrene
lid on cotton wool there will be a great difference in how the
temperature drops over the twenty minutes.
Apparatus
Ø Bubble wrap
Ø Polystyrene
Ø Fibre Glass
be too hot or too cold, this is a safety precaution for me as well as
of 10 to 30 mm Hg for systolic blood pressure and 5 to 10 mm Hg
First of all we decided to use a plastic cup because it was easy to
Before beginning this program, warm up by doing light activity such as riding a stationary bike for 5-10 minutes.
Conducting, as we know it today is less than two centuries old.1 On the other hand time beating; a way of holding players and/or singers together, has been around for several centuries. 1 In the absence of written notation, the leader’s hands indicated the direction of the group. As polyphony entered the musical picture, it became essential that the beats be on target. Interpretation at the time was of no importance. It has been indicated through engravings that in addition to hands, leaders of instrumental and vocal forces utilized a foot, a stick, a pendulum, a handkerchief, or maybe even a piece of paper. 1 In the seventeenth century the element of interpretation entered the music scene, enhancing the role of the leader greatly. This freedom of interpretation increased the conductors responsibility, although no universal practices existed. Gradually the method of time beating approached uniformity; as meters became established, so did the conductors movements.1
high. Also, if a runner is hit exactly at his center of mass, he will
have to be as high, and the players would probably be more accepting of less
heat will stay in the cup and can only escape by rising to the surface
R2 20 minutes --- Intervals – alternating 1 min. light run w/ 1 min. moderate run
If the air pressure inside a ball is changed, then the ball with the greatest air pressure will produce the greatest bounce height. This is because having a greater air pressure means that there will be more molecules pressing and pushing against the bladder of the ball, thus, applying more force to to ball when it rebounds from the ground, and giving it a greater bounce height.
- Temperature was measured after and exact time i.e. 1 minute, 2 minutes, 3 minutes.
... and 10.0 mg/kg in sequential order. The behavioral test only occurred after the second injection of methylphenidate per day. The lever pressing data from last day (how many days?) of each dose will serve as the data point. After the drug phases, abstinence will be introduced and behavioral data will be collected again.
Suspense; Suspense is the intense feeling that an audience goes through while waiting for the outcome of certain events. It basically leaves the reader holding their breath and wanting more information. The amount of intensity in a suspenseful moment is why it is hard to put a book down. Without suspense, a reader would lose interest quickly in any story because there is nothing that is making the reader ask, “What’s going to happen next?” In writing, there has to be a series of events that leads to a climax that captivates the audience and makes them tense and anxious to know what is going to happen. And Suspense, is what “August heat” primarily uses to keep its story so invigorating.
varies from either high to low the blood vessels in the skin is dilating. When the
As discussed in class, submission of your solutions to this exam will indicate that you have not communicated with others concerning this exam. You may use reference texts and other information at your disposal. Do all problems separately on clean white standard 8.5” X 11” photocopier paper (no notebook paper or scratch paper). Write on only one side of the paper (I don’t do double sided). Staple the entire solution set in the upper left hand corner (no binders or clips). Don’t turn in pages where you have scratched out or erased excessively, re-write the pages cleanly and neatly. All problems are equally weighted. Assume we are working with “normal” pressures and temperatures with ideal gases unless noted otherwise. Make sure you list all assumptions that you use (symmetry, isotropy, binomial expansion, etc.).