Please answer all questions

I I H 3. Dene potential energy; what is its SI unit? What is the formula for gravitational potential energy? 4. Dene kinetic energy; what is its 81 unit? What is the formula for kinetic energy? . What is meant by mechanical energy? . Is the total energy of an isolated system alway_s conserved? . Is the total mechanical energy of an isolated system alway_s conserved? 8. Refer to the following: An object (m:100kg) is initially it Lst at point A and starts to move long a frictionless track \\IONUI Set PE=0 at the ground level ie at point B a. Calculate the potential energy of object at points A, B and C b. Calculate the kinetic energy of object at points A, B, and C c. Apply conservation of energy to determine its speed when it reaches point C. PART C ROTATION, TORQUE 1. Explain why \"size\" and \"shape\" of an object is important in rotational motion but not in translational motion. . If the rotation is \"positive\" what does this mean? \"negative\"? . Define moment of inertia; what is its symbol and SI unit? . If the moment of inertia is large, What does that mean? . If the moment of inertia is small, what does that mean? Explain why tight-rope walkers need to carry a long pole What would happen if all the people in the world decided to migrate to the equatorial countries? 8. A student plays on a see-saw with her experimental android robot, Robby. The student has a weight of 275 N and is seated 2.5 m from the axis of rotation. Robby balances her when he is seated 0.7 m from the axis. a. Sketch FBD of the seesaw , label all forces b. What is the torque produced by the student? 0. What is the torque produced by the robot? (1. What is the magnitude of the torque produced by the student's weight? M glowed PART D -MATTER & ATOMS 1. What is the \"size\" of a typical atom? 2. Describe the properties of the subatomic particles that make up the atom 3. What is meant by \"cations\