This graph shows a ball rolling from a to g. the ball starts at point a and rolls to point g.
11. at what letter does the ball have the greatest kinetic energy? .
12. which letter shows the ball when it has the maximum potential energy =
13. which letter shows the ball when it has the least potential energy?
4. wny is point g slightly lower than point a? in other words, why couldn't the ball go back to the same
height at which it started?

11. would be either A or B, which ever one is already rolling.

12. I would say A if it hasn't started moving

13.  D has the least potential energy

14.  The ball can't go as high because it is loosing energy every time and won't be building up as much kinetic energy

The Answers are

11 :   At Point A the ball has greatest kinetic energy

12 : At Point D the ball has maximum potential energy.

13:   At Point A the ball has least potential energy.

14: Point G is slightly lower than Point A Mechanical Energy  ( Kinetic Energy + Potential Energy) of System is not constant  in the given situation.

Considering the reference line at Point A

we can answer the questions

According to this problem

Total Energy of System = Total Kinetic Energy  (KE)  + Total Potential Energy (PE)  + Loss of Energy (1)

Equation (1) shows the energy balance equation for the given system

11 At point A the ball is having maximum Kinetic Energy

12 Since we considered our reference line at point A the farthest point   from A is D so we can say that at point D system has maximum Potential Energy.

13 As the reference line passes through A so the distance of point A from reference line is Zero and hence we can conclude that at A Potential Energy is minimum.

14 Point G is lower than Point A due to loss of energy due to frictional and other resistances so the total mechanical energy of system is not constant.

For more information please follow the link below

link