Development apparatus and image forming apparatus

When dynamic torques are Ts, Ti, and T, respectively, and rotation angle speeds are Rs, R, and R, respectively, at the time of rotations of the developing sleeve and the screws and , the mass of the developer housed in the second agitating chamber is M, the mass of the developer which is present in the space of the side of the developing sleeve when a space formed by the developing chamber and the first agitating chamber is divided is Ms, the mass of the developer which is present in the space of the side of the screw is M, gravitational acceleration is G, each load on the developer by rotations of the developing sleeve and the screws is defined as Wds (mW/g)=Rs×Ts×G/Ms, Wd(mW/g)=RTG/M, and Wd (mW/g)=R×T×G/M, respectively, relationships of 0.5