A loaded penguin sled with weight W rests on aplane inclined at angle θ to thehorizontal (Fig. 6-28). Between the sled and the plane, thecoefficient of static frictionis µs, and the coefficient of kinetic frictionis µk. (a) What is the minimum magnitude of the force parallel to the plane, that will prevent the sled fromslipping down the plane? (b) What is the minimum magnitude F that will start the sledmoving up the plane? (c) What valueof F is required to move the sled up the planeat constant velocity? State your answers in terms of the givenvariables.