A spherical balloon has a surface area of 88cm2. What is the diameter of the balloon to the nearest tenth of a centimetre?
Grade ten math is ridiculous. Why? Just why?
+26400 A spherical balloon has a surface area of 88cm2. What is the diameter of the balloon to the nearest tenth of a centimetre?
\(\begin{array}{rcl} &\text{Surface Area of a Sphere } \\ &\boxed{~ \begin{array}{rcl} A &=& 4 \pi r^2 \qquad \text{diameter } d = 2r \quad r = \frac{d}{2} \\ A &=& 4 \pi \left( \frac{d}{2} \right) ^2 \\ A &=& 4 \pi \frac{d^2}{4} \\ A &=& \pi d^2 \\ \end{array}\\ ~}\\\\ \end{array}\\ \begin{array}{rcll} A &=& \pi d^2 \\ \pi d^2 &=& A \\ d^2 &=& \frac{A}{\pi} \qquad & | \qquad \sqrt{}\\ d &=& \sqrt{\frac{A}{\pi}} \qquad & | \qquad A = 88\ cm^2\\ d &=& \sqrt{\frac{88\ cm^2}{\pi}} \\ d &=& \sqrt{\frac{88}{\pi}} \ cm\\ d &=& 5.2925674284 \ cm\\ \end{array}\\\)
The diameter of the balloon to the nearest tenth of a centimetre is 5.3 cm
Surface area of a sphere is:A=4.Pi.r^2
88=4.3.141592.r^2
88=12.566368.r^2
r^2=88/12.566368
r^2=7.00282 take the sqrt of both sides
r=2.64628cm-the radius of the balloon.
Diameter=2.64628 X 2=5.3cm-the diameter of the balloon.
+26400 A spherical balloon has a surface area of 88cm2. What is the diameter of the balloon to the nearest tenth of a centimetre?
\(\begin{array}{rcl} &\text{Surface Area of a Sphere } \\ &\boxed{~ \begin{array}{rcl} A &=& 4 \pi r^2 \qquad \text{diameter } d = 2r \quad r = \frac{d}{2} \\ A &=& 4 \pi \left( \frac{d}{2} \right) ^2 \\ A &=& 4 \pi \frac{d^2}{4} \\ A &=& \pi d^2 \\ \end{array}\\ ~}\\\\ \end{array}\\ \begin{array}{rcll} A &=& \pi d^2 \\ \pi d^2 &=& A \\ d^2 &=& \frac{A}{\pi} \qquad & | \qquad \sqrt{}\\ d &=& \sqrt{\frac{A}{\pi}} \qquad & | \qquad A = 88\ cm^2\\ d &=& \sqrt{\frac{88\ cm^2}{\pi}} \\ d &=& \sqrt{\frac{88}{\pi}} \ cm\\ d &=& 5.2925674284 \ cm\\ \end{array}\\\)
The diameter of the balloon to the nearest tenth of a centimetre is 5.3 cm
