An enclosed gas exerts a pressure p on the walls of a container. this pressure is directly proportional to the temperature t of the gas, measured in kelvin. if the pressure is 7 lb per square inch when the temperature is 420°k, find the constant of variation.

Sara goes on a slingshot ride in an amusement park. she is strapped into a spherical ball that has a radius 3*10^2 of centimeters. what is the volume of air in the spherical ball? use this formula: volume of a sphere=4/3pi,r^3 , where r is the sphere’s radius.