answer the question below : a. At Dayton, OH, what is the solar time correspondi
ID: 236859 • Letter: A
Question
answer the question below :
a. At Dayton, OH, what is the solar time corresponding to 11:00 AM (clock time) on Feb. 3? (Dayton is located at 84oW longitude)
b. Using the previous problem for Dayton, OH, what is the solar altitude angle and azimuth angle? (The latitude of Dayton is 39.7o N)
c. Using the previous problem for Dayton, OH, what is the solar angle of incidence on a surface tilted at 45o from the horizontal, facing southeast?
d. If during the day there is 200 2 Wmsolar from 8:00 am to 10:00 am, 600 2 Wmfrom 10:00 am to 12:00 noon, 900 2 Wmfrom 12:00 noon to 3:00 pm, 300 2 Wmfrom :00 pm to 6:00 pm, and 100 2 Wm from 6:00 pm to 7:00 pm, how many peak sun hours were there in that day?
Explanation / Answer
a. Solar time= LST+(4min/degree)(LSTM-long) +ET
LST= local standard time or clock time( LST=DST(day light saving time)- 1 hour=11-1=10 AM
Long= local longitude of position of interest= 84 degree W
LSTM= local longitude of standard meridian=15 degree* (long/15 degree)=15*(84/15)
=15*5.6=15*6=90( round to integer)
ET= equation of time
ET=9.87 sin(2D)-7.53 cos(D)-1.5 sin(D)
where D=360 degree(N-81)/365
N=34
D=360(34-81)/365
=360(-47)/365=360*0.12=43.2degree
ET=9.87sin(2*43.2)-7.53cos(43.2)-1.5sin(43.2)
=-9.87*0.99+7.53*0.72+1.5*1.5*0.68
=9.77+5.42+1.02
=-9.77+6.44
=-3.33 min
Apparent solar time= (LST+ 4 min)(LSTM- long)+ET
=10+(4 min/deg)(90-84)-3.33
=10+24-3.33
=10+20.67min
=10:21AM
b.H= hour angle( no of minutes past midnight.AST)-720 min/4 min/deg
=(60*10+21)-720 min/4 min/deg=621-720/4 min/deg=-24.7deg
decliantion angle=23.45 degree sin( N+284/365*360)
=23.45degree sin(34+284/365*360
=23.45degree sin(0.87*360)
=23.45*sin(313.2)
=23.45*0.72
=16.8degree
Now. solar altitude angle
sin (beta 1)=cos(L)cos(delta)cos(H)+ sin(L)* sin(delta0
L= latitude
H= hour angle
delta= decliantion angle
beta 1=arc sin(cos(39.75)cos(16.8)cos(24.7)+ sin(39.75)sin(16.8)
=arcsin(0.76*0.95*0.91)+ (0.63*0.28)
=arc sin( 0.65+0.17)
=arcsin(0.82)
=0.014
=
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.