10.8 The Volume of a Sphere
Transcription
10.8 The Volume of a Sphere
10.8 The Volume of a Sphere 1. A cone has a radius of 8 cm and is 15 cm tall. What is the lateral area of the cone? What is the SA of the cone? What is the volume of the cone? 2. A roof of a house has a surface area of 1,025 square feet. A square of shingles cover 90 square feet and there are 3 bundles/square. If a square costs $110 and a bundle costs $40 how many of each should you order and what will your total cost be for the shingles? First figure out the # of squares Next figure out # of bundles. Add costs together. Volume of Spheres: ex: the amount of water that can be held in a spherical water balloon. 1. The volume of a sphere is found by the following formula: V = 4 3 3 πr 2. If the radius of a sphere is 15 cm what is the volume? 3. A soccer ball has a circumference of 24”. What is the volume of the ball? Remember you must first find the radius in order to do the volume problem. The circumference of a circle is as follows: C = 2πr. The formula to find the volume of a sphere is V = 4/3 πr3 The radius of the sphere for this problem is r = 3.82" 4. The area of a small circle of a sphere may be calculated by the following formula: ________________, where “r” represents the RADIUS of the great circle and “h” represents the height from the great CIRCLE to the small CIRCLE. In other words the radius of the small circle is really equal to a leg of a right triangle! 5. The area of the great circle may be found by the following formula: A = πr2 6. Find the area of a small circle of a sphere if the radius of the sphere is 10 cm and the distance from the great circle to the small circle is 6 cm. 7. Find the area of the ring below: The formula for the area of a ring is as follows: A = _______________, GREAT CIRCLE and “h” where r is the radius of the _________________ is the height from the center of the great circle to the _____________ _____________. inner circle Radius of cylinder is 7 inches. Height from center point to inner circle is 2.5 inches. 8. Find the volume of the following spheres: Radius = 1cm Diameter = 8.2cm3 Circumference = 26 9. Give the radius of the sphere with the given volume.