Tuesday October 9 th Daily Check: part*part=part*part outside*whole=outside*whole

Daily Check

Surface Area of a Sphere

Volume of a Sphere

A sphere is inscribed in a cube of volume 125 cubic meters. What is the surface area and volume of the sphere? Give an exact answer and an answer rounded to the nearest hundredth.

Volume = Find the radius. Round to the nearest hundredths.

Volume of a Sphere Circumference of Great Circle = 14 cm Find the volume of the sphere. Round to the nearest hundredths.

Volume of a Sphere Volume = Find radius. Round to the nearest hundredths.

Comparing Ratios

Sphere A Sphere B Radius of Sphere ARadius of Sphere B 3 cm6 cm How much bigger? 2 times bigger

Sphere A Sphere B SA of Sphere ASA of Sphere B 3 cm6 cm How much bigger? 4 times bigger 36  cm  cm 2

Sphere A Sphere B V of Sphere AV of Sphere B 3 cm6 cm How much bigger? 8 times bigger 36  cm  cm 3

Sphere A Sphere B Radius of Sphere ARadius of Sphere B 3 cm15 cm How much bigger? 5 times bigger

Sphere A Sphere B SA of Sphere ASA of Sphere B 3 cm15 cm How much bigger? 25 times bigger 36  cm  cm 2

Sphere A Sphere B V of Sphere AV of Sphere B 3 cm15 cm How much bigger? 125 times bigger 36  cm  cm 3

There is a pattern that can save you some work!

SET UP A TABLE LIKE THIS Times biggerSphere ASphere B RADIUS r SA r2r2 V r3r3

If the radius of a sphere is doubled, what happens to its volume? V is 8 times bigger Times biggerSphere BSphere A RADIUS r SA r2r2 V r3r3 r = 2 r 3 = 8

If the radius of a sphere is quadrupled, what happens to its surface area? SA is 16 times bigger Times biggerSphere ASphere B RADIUS r SA r2r2 V r3r3 r = 4 r 2 = 16

The radius of sphere A is 1 cm and the radius of sphere B is 2 cm. The SA of sphere A is 4  in 2, what is the SA of sphere B? 16  in 2 Times BiggerSphere ASphere B RADIUS r SA r2r2 V r3r3 2 cm r 2 = 4 1 cm 4  r = 2

The radius of sphere B is 3 times bigger than the radius of sphere A and the V of sphere A is 10  in 3, what is the V of sphere B? 270  in 3 Times BiggerSphere ASphere B RADIUS r SA r2r2 V r3r3 r 3 =  r = 3

The SA of sphere B is 4 times bigger than the SA of sphere A. If the radius of sphere B is 20 m, what is the radius of sphere A? 10 m Times biggerSphere ASphere B RADIUS r SA r2r2 V r3r3 r 2 = 4 20 r = 2

The V of sphere B is 125 times bigger than the V of sphere A. If the radius of sphere B is 45 ft, what is the radius of sphere A? 9 ft Times biggerSphere A Sphere B RADIUS r SA r2r2 V r3r3 r 3 = r = 5