Saturday

August 30, 2014

August 30, 2014

Posted by **saru** on Friday, October 18, 2013 at 1:25am.

Calculate the average solar power per square meter (in Watts) on a horizontal surface for a day when the sun goes through the zenith at noon.

The sun goes through the zenith exactly twice a year on latitudes that are close to the equator. Take the angle to the sun into account.

- Physics pls anyone can help me? its urgent -
**bobpursley**, Friday, October 18, 2013 at 3:56amThe incident power is given by

power=Powermax*sinTheta

where theta is the angle measured from horizontal East to the sun. At noon, Theta=90 degrees This takes 12 hours, so theta=time*PI/12, where time is in hours, ie, noon is time 6

avg=total energy /time

lets measure energy in kw-hr

total energy= INTEGRal power*dtime from time=0 to 12

total energy= INT 1kw*sin(PI*t/12 )dt

= -1kw* (cosPIt/12)*12/PI from zero to 12

= -12/PI * (cos (PI) -cos0)

= -12/PI ( -1 -1)=24/PI kw-hr

average power= total energy/(12)

= 2/PI kw-hrs

check this.

- Physics pls anyone can help me? its urgent -
**saru**, Friday, October 18, 2013 at 4:15amIt should be in watts. so 2/PI kw-hr should be 2*1000/(PI*3600)watts or ? please

- Physics pls anyone can help me? its urgent -
**Steve**, Friday, October 18, 2013 at 4:28amsomething got mangled in the units

kw-hr is energy

kw is power

Better check the units in the math above.

**Related Questions**

Chemistry-pls help urgent - Posted by candy on Tuesday, October 12, 2010 at 5:...

Physics - A child pulls a wagon along level ground. The handle with which she ...

science - pls. pls. pls. somebody help me...you see im on a science class and i ...

physics.pls help - How do you know what element is chemically active on the ...

physics.pls help - can you help me to isolate the ''t'' in this formula. d=V1t+1...

physics.pls help - Why is it important to asaume that a rope under tension is ...

physics.pls help - A 100g bird sits in its nest. what is the Fnet(net force) in ...

Chemistry :'( - (d) Which of the following sets of quantum numbers is not ...

geography - hi,i have make a project on hurricane Katrina on disaster management...

physics urgent - A 1.5 m tall man stands 2 m in front of a flat wall mirror. ...