The centrifugal force of an object moving in a circle varies jointly with the radius of the circular path and the mass of the object and inversely as the square of the time it takes to move about one full circle. A 6 gram object moves in a circle with a radius of 75 cm every 3 seconds has a centrifugal force of 5000 dynes. Find the centrifugal force of a 2.5 gram object moving in a circle with radius 40 cm every 4 seconds.​