The volume of a sphere is given by:

`V = frac(4)(3)pir^3`

What is the volume of a sphere of diameter 6 cm? Give your answer to 3 significant figures.

For a sphere: | Volume | `= frac(4)(3)pir^3` |

Substitute | `=frac(4)(3)pi(6)^3` | |

`= 904.778` |

Answer: 905 cm^{3}

A sphere and a cylinder have the same volume. If the radius of the sphere is 9cm, what is the height of the cylinder?

Cylinder: | Volume | `= pir^2l` |

Sphere: | Volume | `= frac(4)(3)pir^3` |

Both equal | `pir^2l` | `= frac(4)(3)pir^3` |

Divide both sides by `pi` | `r^2l` | `= frac(4)(3)r^3` |

Divide both sides by `r^2` | `l` | `= frac(4)(3)r` |

Substitute | `l` | `= frac(4)(3)(9)` |

`= 12` |

Answer: 12 cm

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