Suppose that a tunnel could be drilled straight through the earth from the North Pole to the South Pole and the air was evacuated. An object dropped from the surface would fall with acceleration where g is the acceleration of gravity at sea level, is the radius of the earth, and s is the distance of the object from the center of the earth. (The acceleration due to gravity is equal to zero at the center of the earth and increases linearly with distance from the center.) What is the magnitude of the velocity of the dropped object when it reaches the center of the earth