Answer to Question #23224 in Mechanics | Relativity for Julietta Holguin
Your pancake recipe calls for 1.5 cups of flour to make 20 four-inch pancakes. But you want to make
twelve eight-inch pancakes. How much flour should you use?
Flour which needed to make one four-inch pancake: 1.5/20 = 0.075 We'll assume that the thickness of the pancakes with diameter four-inch and eight-inch are the same. A pancake is a cylinder. A cylinder with radius r and height h inch has a volume of V cubic inch given by V = П*h*(r^2) П = 3.14 V'/V = (r'^2)/(r^2) =(d'/2)^2/(d/2)^2 = (d'/d)^2 V', d' - volume and diameter of eight-inch pancake; V, d - volume and diameter of four-inch pancake; Flour which needed to make one eight-inch pancake: ( 0.075*V')/V =0.075* (d'/d)^2 = 0.075 * 4 = 0.3 Flour which needed to make twelve eight-inch pancake: 12 * 0.3 = 3.6 Answer: 3.6 cups of flour.