2. a. wheel of mass M and radius R is standing vertically on the oor. We want to exert a horizontal force at its axle so that it will climb a step against which it rests. The step has height it where it s: R. 1|illihati'i-iinirnurn force F is needed? A. {5 points) As the wheel climbs the step against which it rests, what is its axis of rotation? What physical assumptions will you make to solve this problem? B. {5 points) Draw an extended free body diagram for the wheeL Be sure to show the axis of rotation the center of mass, and any forces which act on the wheel. C. (5 points) Determine a symbolic expression for the minimum force needed to cause the wheel to climb the step. D. [5 points} Does your answer make sense? Check this in the following ways: i} Suppose the radius of the wheel increased. Explain how this change would this affect the force needed to climb the step. Does your expression match your intuition? ii) Suppose the height of the step increased. Explain how this change would this affect the force needed to dimb the step. Does your expression match your intuition? iii} Suppose the mass of the wheel increased. Explain how this change would this affect the force needed to climb the step. Does your expression match your intuition