Solving Variation Problems Test

When swimming underwater, the pressure in your ears varies directly with the depth at which you are swimming. At 15 feet, the pressure is approximately 6.45 pounds per square inch (psi). Find the pressure at 22 feet.

The amount of water emptied by a pipe varies directly with the square of the diameter of the pipe. When the water flow is constant, a water treatment facility receives 560 gallons of water in one hour from a pipe with a diameter of 10 inches. Assuming a constant water flow, how much water would the water treatment facility receive in one hour from a pipe with a diameter of 13 inches?

The illumination provided by a car's headlight varies inversely with the square of the distance from the headlight. If a car's headlight produces an illumination of 15 foot-candles at a distance of 20 feet, what is the illumination when the distance is 25 feet?

The amount of simple interest earned varies jointly with the principal (amount invested) and time. If an investment of $1300 for a 4-year period earns $364 in simple interest, how much will an investment of $2400 earn in simple interest over a 12-year period?

The volume of gas varies directly with the temperature and inversely with the pressure. If natural gas occupies a volume of 2.08 liters at 400 K and a pressure of 15 newtons per square centimeter, find the volume at 250 K and a pressure of 20 newtons per square centimeter.