Warm up Notes Preliminary Activity Activity For Fun Surface area and Volume of a sphere
Back Review Quiz 1. A tank containing milk has an elliptical cross-section of area 8.7 m 2. If it holds 95.7kL of milk, how long is the tank? (remember 1m 3 = 1kL) 2. Find, correct to 2 significant figures a) the length of arc EI (l = θ x 2πr) 360 b) the area of sector PIE ( A = θ x πr 2 ) Solve 9w + 24 = 3w 4. evaluate (2.7 x ) 2 5. Use the compound interest formula A = P(1 + r) n to calculate the amount to which a principal of $5000 will grow after 4 years, if it is invested at 12.5% p.a. paid six monthly m 2.a) 7.3 cm b) 29cm 2 3. w = x $
Back The surface area of a sphere is calculated using the formula A = 4πr 2 where r = radius of the sphere The volume of a sphere is calculated using the formula V = 4 / 3 πr 3 where r = radius of sphere
Back Examples 1. An asteroid in the shape of a sphere has a diameter of 325 m. What is its surface area to the nearest hectare? SA = 4πr 2 = 4 x π x = m 2 = 33 ha 2. Calculate the volume of the above asteroid. V = 4 / 3 πr 3 = 4 / 3 x π x m 3 = 1.8 x 10 7 m 3
Back 41.7% 56.3% 75.7% Do Exercise 2.07 page 64 Q 1 - 8
Back $1 104 $ $ % $ %
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