A fixed number of moles of an ideal gas are kept in a container of volume V and an absolute temperature T. If T and V are both doubled, the new r. m.s. velocity of the molecules in the gas will be times the original r. m.s. molecular velocity. A: 1/4 B: 1/2 C: 1/sqrt(2) D: equal to E: sqrt(2) F: 2 G: 4 If T doubles while V is held constant, the new net internal energy of the gas will be times the original internal energy of the gas.

If the temperature and volume ot a gas increases, the r.m.s. velocity of the molecules in the gas will be 2  times the original r.m.s. molecular velocity.

If T doubles while V is held constant, the new net internal energy of the gas will be 2 times the original internal energy of the gas.

Explanation:

Temperature and root mean square velocity are directly proportional to one anoth. If the temperature increases, root mean square velocity also increases and vice versa, while temperature is also directly proportional to the internal energy of the gas molecules, higher the temperature, higher will be the internal energy and lower the temperature so internal energy will be decreased.

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.