could you provide examples that answer these questions with solutions. for example number $5.$ what is work? example: a force of $50$N is applied to push a box horizontal surface for a distance of $10$m$.$ solution: w$=$f$.$d$.$cos degree w$=50$N$.10$m $.$ cos$0=500$j

Question $1.$ Why is the acceleration of uniform circular motion directed toward the centre of a circle? $2.$ Using circular motion to approximate elliptical orbits, how can you describe the motion of planets, moons natural satellites and satellites artificial satellites $$ using mathematical relationships formulas $3.$ How was Newton able to use Kepler laws that described the motion of planets as elliptical orbits around the sun, to develop his law of universal gravitation? $4.$ What is the relationship between the kinetic energy due to motion $$ the potential energy stored and the total mechanical energy of an object in a closed isolated system? $5.$ What is work? $6$How does the mechanical energy change in a system that is not isolated? $7$ What is power and how does it relate to work?