please show me how to solve symbolically while solving the problem

7. Two identical wheels are moving on horizontal surfaces. The center of mass of each has the same linear speed. However, one wheel is rolling, while the other is sliding on a frictionless surface without rollingEach wheel then encounters an incline plane. One continues to roll up the incline, while the other continues to slide up. Eventually they come to a momentary halt, because the gravitational force slows them down. Each wheel is a disk of mass 2.85 kg. On the horizontal surfaces the center of mass of each wheel moves with a linear speed of 5.88 m / s. (a), (b) What is the total kinetic energy of each wheel? (c), (d) Determine the maximum height reached by each wheel as it moves up the incline. 8. One end of a thin rod is attached to a pivot, about which it can rotate without friction. Air resistance is absent. The rod has a length of 0.84 m and is uniform. It is hanging vertically straight downward. The end of the rod nearest the floor is given a linear speed v_{0} so that the rod begins to rotate upward about the pivot. What must be the value of such that the rod comes to a momentary halt in a v_{0} straight-up orientation, exactly opposite to it initial orientation? 9. A playground carousel is free to rotate about its center on frictionless bearings, and air resistance is negligible. The carousel itself (without riders) has a moment of inertia of 125kg * m ^ 2 When one person is standing on the carousel at a distance of 1.50 m from the center, the carousel has an angular velocity of 0.600 rad/s However, as this person moves inward to a point located 0.920 m from the center, the angular velocity increases to 0.8 rad/s What is the person's mass