a 1 kg emery stone measuring 20 cm redium, is rotating with an angular speed of 39 revolutions per minute, when the motor is turned off. What tangent force is applied to the wheel so that it stops at 10 revolutions. a. 12,24 Rand/s b. 13,24 Rand/s c. 10,4 Rand/s d. 124 Rand/s

(a) assume the equation x = at^3 + bt describes the motion of a particular object, with x having the dimension of length and t having the dimension of time. determine the dimensions of the constants a and b. (use the following as necessary: l and t, where l is the unit of length and t is the unit of time.) (b) determine the dimensions of the derivative dx/dt = 3at^2 + b. (use the following as necessary: l and t, where l is the unit of length and t is the unit of time.)