# college earth science and astronomy

posted by on .

This isn't homework as much as I am trying to learn this on my own. I am trying to perform an experiment on solar power.

I measured and recorded the volume (V= 250 mL) and mass (M= 250 g) of water in a cup. I then recorded the initial temperature(32 degrees celcius) of the water.

I covered the cup in plastic and placed in the sun for 10 mins.

I removed the plastic and recorded the final temperature (34.5 degrees celcius) then I record the difference of 2.5 degrees celcius.

I have calculated the cups diameter at 9 cm and the surface area of the water at 3.14 * 4.5 *4.5=63.585.

Now this is where I get totally lost.

I must now determine
energy= _______Calories

Then solar energy flux =_____cal/cm^2min

Then solar energy flux=_____cal/m^2min.

Then total solar output per minute=_____calories.

Can anyone help guide me through arriving at the correct answer?

• college earth science and astronomy - ,

calories absorved=masswater*1*deltaTemp
= 250*2.5 calories

solar flux= 250*2.5/(63.6*10) cal/cm^2*min
lets see there is 100^2 cm^2 in a m^2
solar flux= 250*2.5*100^2/(63.6*10) cal/m^2 min

solar output= solar flux* area*time

• college earth science and astronomy - ,

Thank you very much bobpursley! This has been quite the challenge to learn without the benefit of a teacher. I want to run my answers past and see if I have calculated correctly.

energy= 250 * 2.5 = 625 Calories

Then solar energy flux will be 250 *2.5 (625) / 63.6 * 10 (636) cal/cm^2*min

Then solar energy flux is 250*2.5*100^2 (6,250,000) / 63.6*10 (636) cal/m^2min. = 9827.044025

Then total solar output per minute= 9827 * 63.6 * 10= 6,249,972 calories.

This doesnt look right to me.