What would happen to the density of an ideal gas if its pressure is cut in half and its Kelvin temperature decreases by 10 times the original temperature? Be sure to explain in words and numbers!!!

The density increases by 5 times

Explanation:

We can solve this problem by using the equation of state of an ideal gas:

where

p is the pressure of the gas

V is its volume

n is its number of moles

R is the gas constant

T is the Kelvin temperature

Since n and R are constant during a gas transformation, we can rewrite the equation as

In thhis problem we have:

, since the pressure of the gas is cut in half

, since the gas temperature decreases by 10 times

Therefore solving for V2, we find how much does the volume of the gas change:

So, the volume decreases by 5 times.

The density of the gas is given by

where m is the mass of the gas and V its volume. Here, the mass of the gas remains constant: so, the density is inversely proportional to the volume. Therefore, if the volume decreases by 5 times, the density will increase by 5 times.

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.

the answer is 1260

you spend 7 hours in school for 1 school day with 5 school days in 1 school week with 36 school weeks in a school year.

7*5*36= 1260 it's all about multiplying