A508−g piece of copper tubing is heated to 89.5°c and placed in an insulated vessel containing 159 g of water at 22.8°c. assuming no loss of water and a heat capacity for the vessel of 10.0 j/°c, what is the final temperature of the system (c of copper = 0.387 j/g·°c)?

Teq=37.85°C

Explanation:

Hello, I'm attaching a picture in which the mathematical procedure is given.

- the specific heat of water was extracted from Cengel's thermodynamics book.

- take into account that since the system is isolated, no dissipation or absorption of energy is presented.

- we assume that the initial temperature of the vessel is equal to the water's initial temperature.

- the symbolic T is the very same temperature when the equilibrium is reached.

Best regards.

it is important to conserve water because there is very limited amount of freshwater here on earth and if we are not smart about how we use it we will only be runnning out of our supply faster than neccessarry.

1. the question asks the most appropriate, which seems to rule out "all of the above." your choice appears to be the correct one.

2. the protocol described is good for identifying correlation, but not cause and effect. for cause/effect, you need to devise a protocol that will assign the treatment (or not) to groups that have essentially the same "demographics" with respect to all the other variables. your choice regarding control group seems appropriate. random assignment of treatment (choice d) may be appropriate also. (i think you can argue that b and d are just different descriptions of the same method.)

3. d will randomize the birds, but may not guarantee there are 10 in each group. e will do both, so seems the better choice.

comment on question 2

based on the problem statement, it seems clear that confident, attentive drivers are more likely to use daytime running lights. so, the protocol might need to be devised in such a way that the lights would be turned on or off without the driver's knowledge. (an attentive driver will figure it out.) assigning a confident, attentive driver to a group required to drive without running lights might mess with his/her confidence and attentiveness. you don't want your experiment to do that. (nor do you want the experiment to subject a driver to greater risk of accident as a consequence of driving without running lights.) experiments involving human safety are always problematic.