A person who did not pay attention in physics class is standing in their bare feet under a tree during a thunderstorm. A lightning strike hits the tree. A burst of current lasting 500 ms passes through to the ground. During this time, the potential difference between their feet is 20,000 V. The resistance between one foot and the other is 500 Ω,

What is the current in their body?
How much energy is transformed in their body by the lightning?
What happens to the transformed energy?