Acid-Base reaction - treating a jellyfish sting

Watch the following video clip.
Neutralising a jellyfish sting

If an acid (Vinegar) is effective in reducing pain, neutralising the sting, what does this tell us about the sting of a jellyfish?

What causes car crashes?

Complacency, driver error, car condition and the road conditions are all contributing factors to car collisions. To find out more watch some of the following video clips
•Crash test compilation 
•Crash comparison different speeds
•Newton’s law of Inertia
•Crash with and without seatbelt
•Understanding car crashes
•Jeremy Clarkson on breaking distances