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Sun 3 Sep, 2017 11:12 am

I am trying to figure out the torque applied to 2 wheels counter-rotating at 4,000 rpm when a tennis ball is squeezed between them .This is how a tennis ball machine propels a ball forward. I know the distance between the counter-rotating wheels so I know how much force it takes to squeeze the ball that much. It's about 60 lbs, so 30 lbs on each wheel. The traditional formula of Torque = Distance * Force * sin(theta) does not work because the force is being applied in line with the radius against the edge of each wheel towards the axis or rotation which is sin(0 deg) or sin (180 deg) which both yield 0 as the torque applied but that cannot be the case.

Does anyone know? Maybe there is a way to translate perpendicular force against the wheel edge into tangential force when the wheel is rotating at a certain rpm?