Pressure angle 25 degrees. Earlier gears with pressure angle 14.5 were commonly used because the cosine is larger for a smaller angle, providing more power transmission and less pressure on the bearing; however, teeth with smaller pressure angles are weaker. To run gears together properly their pressure angles must be matched. The pressure angle is also the angle of the sides of the trapezoidal teeth on the corresponding rack. The force transmitted during the mating of gear teeth acts along the normal. This force has components along the pitch line and the other along the line perpendicular to the pitch line. The
360 Degrees of Billy Paul was similarly enthusiastic in discussing how Paul's sound developed over the years from the early club jazz of "Feelin' Good at the Cadillac Club" (1968) to the merging of jazz and soul on "Going East" (1971): "and then we did Billy's "360 Degrees" album and it all came together with "Me & Mrs. Jones." During his appearance on "Soul Train" in October 1972, Paul was asked by host Don Cornelius whether he had a jazz background. Paul used the opportunity to promote his new album and highlight its diverse styles: “That's very correct. I've been singing since I was 11.