Do you know how many independent variables there are in this question? The size, weight, age, species, genus and diet of the koala. The weight and size of the chariot, the circumference of the wheels and the length of the rope. They can all change the answer. Please be more specific.
Koalas do not take each other's food. If two koalas reach for the same sprig of gum leaves, they will simply pull at it until one of the koalas gets to keep the leaves. Koalas are not territorial about their food.
Koalas do not take showers.
Balls
In the Olympics
I think it was the roman times
Not much
you have to wait for the ref to drop a white cloth to start, many people died form such races. Laps were normally between 7-10, and take around 15 minutes to complete the race. Most chariot races had knives to free themselves if a chariot was to crash and they were to get tangled up.
Koalas are herbivores, plant eaters. Doesn't take much to chase down some leaves.
It courage and pride but some discipline
Step one: Take a plastic wagon with a flat base and two wheels that doesn't have sides. Hopefully, the wagon will have slots in the base for planks of wood to be later put in. (the reason that I don't suggest for you to build a flat base is that the base will not be sturdy and will collapse and cause fatal injuries to you and the rider.) Step two: Take four 2'x4'x8" and cut down into the appropriate lengths. Make sure that they slope down in the back to create the chariot effect. Then, place them into the slots at the bottom of the chariot base. This will create the frame for the chariot. Step three: Cut cardboard so it will fit around the frame and paint. Step four: Take two more 2'x4'x8" planks and secure them to the front of the chariot, creating the way to pull the chariot around. Yeah, yeah. I know it's not the most detailed description, but hopefully it will give you an idea as to how to build something like this.
Dingos, dogs, foxes and cats. Birds such as eagles and hawks will take young koalas if the opportunity present itself.
Chariot races took place in a special arena called a "circus". In the east it was called a hippodrome. Although other ceremonies and events could be held in a circus, they were principally for chariot races.