radius

When the circumference of a circle is increased from 10 pi inches to 15 pi inches, by how many inches is the radius increased? C = 2pir Smaller circle: 2pir = 10pi Divide each side by 2pi: r = 5 Larger circle: 2pir = 15pi Divide each side by 2pi: r = 7.5 Difference = 7.5 - 5 = 2.5 or 2&1/2

Three tennis balls each have a radius of 2 inches. They are put into a 12 inch high cylinder with a 4 inch diameter. What is the volume of the space remaining in the cylinder? Volume of each ball is 4/3 πr^3 V = 4/3 * 3.1415 * 2^3 V = 1.33 * 3.1415 * 8 = 33.41 cubic inches The volume of 3...

When a circle's radius triples, what happens to its area? A = πr^2 When r = 3r, then we have: a = π(3r)^2 A = 9(πr^2) This means Area increases by 9x

What is the formula for the volume of a cylinder? The Volume (V) of a cylinder with radius (r) and height (h) is: V = πr^2h

Fantasia decided to paint her circular room which had a diameter of 25 feet. She started painting in the center and when she had painted a circle with a 5-foot diameter, she used one quart of paint. How many more quarts of paint must Fantasia buy to finish her room? The area formula for a...

The button on Alice's shirt has a diameter of 8 millimeters. What is the button's radius? Radius = Diameter / 2 Radius = 8/2 Radius = 4

if my diameter is 19 inches, what is my radius? Radius = Diameter/2 Radius = 19/2

A penny has a diameter of 19 millimeters. What is the radius of the penny. D = 2r To solve for r, we divide each side by 2: r = D/2 Plugging in D = 19, we get: r = 19/2 or 9.5

A circular balloon is inflated with air flowing at a rate of 10cm3/s. How fast is the radius of the ballon increasing when the radius is 2cm? The volume (V) of the balloon with radius (r) is: V = 4/3πr^3 Differentiating with respect to t, we get: dV/dt = 4/3π * 3r^2 * dr/dt dV/dt = 4πr^2 *...