- A vehicle is a kind of object
- A wagon is a kind of vehicle
- Therefore, a wagon is a kind of object

- A wagon is a kind of object
- Rolling is a kind of motion
- So, a wagon rolling is an example of an object in motion

- A wagon rolling is an example of an object in motion
- An example of mechanical energy is an object in motion
- So, a wagon rolling is an example of mechanical energy

So, a wagon rolling is an example of mechanical energy
Question: Which event is the best example of mechanical energy?
Context: - A vehicle is a kind of object 
- An example of mechanical energy is an object in motion 
- A wagon is a kind of vehicle 
- Rolling is a kind of motion