M mevturnbull Guest Sep 2, 2009 #1 inside of a warm house.? If its surface area increases 7.0% by what percentage does the radius of the balloon change?
inside of a warm house.? If its surface area increases 7.0% by what percentage does the radius of the balloon change?
A aerogel Guest Sep 2, 2009 #2 New surface area=1.07A, where A is the old surface area. If A=4*pi*r^2, then 1.07A=4*pi*R^2, where R is the new radius. Substituting in A and canceling out 4pi, you get: 1.07r^2=R^2, so R=1.0344r , which means the radius increases by about 3.44%.
New surface area=1.07A, where A is the old surface area. If A=4*pi*r^2, then 1.07A=4*pi*R^2, where R is the new radius. Substituting in A and canceling out 4pi, you get: 1.07r^2=R^2, so R=1.0344r , which means the radius increases by about 3.44%.
