A frozen popsicle is sitting outside in the sun. How will energy travel between the cold popsicle and the warm air around the popsicle?

When the frozen popsicle sitting outside in the Sun is exposed to warm air, energy will travel between the popsicle and the warm air as follows;

1) Convection current

Heat will be gained by the frozen popsicle by coming into contact with fresh warm air as the air flows around the popsicle while the cooling of the warm air will cause the water vapor in the air to condense and form the visible mist

In turn the popsicle will gain heat resulting in melting of the ice

2) Conduction

As the some of the mist from the air settles on the popsicle, they share their heat resulting further melting of the popsicle

3) Radiation

Radiated heat energy from the Sun is absorbed by the popsicle resulting in the melting of the popsicle

Explanation:

answer: the rate of diffusion increases with increase in temperature.

increase in temperature, increases the molecular/particles speed (kinetic energy. diffusion means movement of particles through the material.

generally, the heavier the particle the more it interacts with the environment and more the temperature matters. so higher temperature results in higher diffusion.

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.