Sunday

December 21, 2014

December 21, 2014

Posted by **Johnny** on Wednesday, September 1, 2010 at 10:17am.

1. A spherical balloon is partially blown up and its surface area is measured. More air is added increasing the volume of the balloon. If the surface area of the balloon expands by a factor of 2.0 during this procedure, by what factor does the radius of the balloon change?

2. A poster advertising a student election candidate is too large according to the election rules. The candidate is told she must reduce the length and width of the poster by 20.0%. By what percentage will the area of the poster be reduced?

- Physics -
**drwls**, Wednesday, September 1, 2010 at 11:04am1. Area is proportional ot the square of radius. Therefore, to double the area, muliply the radius by sqrt2 = 1.414

2. (0.8)^2 = 0.64 is (new area)/(old area)

The reduction percent is 1-0.64 = 36%

This is really not physics.

**Answer this Question**

**Related Questions**

Calculus: need clarification to where the #'s go - Air is being pumped into a ...

Calc - Air is being pumped into a spherical balloon so that its volume increases...

Calculus - Air is being pumped into a spherical balloon so that its volume ...

calc - Air is being pumped into a spherical balloon so that its volume increases...

calculus - Air is being pumped into a spherical balloon so that its volume ...

calculus - Air is being pumped into a spherical balloon so that its volume ...

Calculus - Air is being pumped into a spherical balloon so that its volume ...

AP calculus AB - A spherical balloon is being filled with air in such a way that...

help on calculus - A spherical balloon is being filled with air in such a way ...

related rates problem-calculus - A spherical balloon is being filled with air in...