A rectangular prism has a length of 50 cm, a width of 25 cm, and a height of 10 cm when it is at rest with respect to an inertial frame, S. The density of the rectangular prism is 2640 kg/m ³. Determine the density of the rectangular prism when it is moving in a straight line parallel to its length at a speed of 0.75c with respect to the frame S.