Question 224559
1-mile=5,280 feet
W=weight c= constant r= distance from core
:
1. solve the equation w=Cr^-2 for r
Multiply both sides by r^2, results:
wr^2 = C
r^2 = {{{C/w}}}
r = {{{sqrt(C/w)}}}
:
2. suppose that an object is 100 pounds when it is at sea level. find the value of c that makes the equation true. (Sea level is 3,963 miles from the center of the earth)
:
From the above we know C = w*r^2.
 Assume they want the distance from the center of the earth in feet
C = 100*(5280*3963)^2
C = 4.3784(10^16)
:
An example: 100 lb person at sea level would be ? at 10,000 ft
:
w = c*r^-2
w = 4.3784(10^16) * ((5280*3963)+10000)^-2
w = 99.904 lb