A cord is wrapped around the rim of a solid uniform wheel 0.250m in radius and of mass 9.20 kg. A steady horizontal pull of 40.0 N to the right is exerted on the cord, pulling it off tangentially from the wheel. The wheel is mounted on frictionless bearings on a horizontal axle through its center. (a) Compute the angular acceleration of the wheel and (b) the acceleration of the part of the cord that has already been pulled off the wheel.