A somewhat silly, but still amusing piece from Live Science:

Given that blondes generally have about 140,000 hairs on their heads, her hair should easily support the weight of many, many princes. However, there is more to this story.

If Rapunzel simply let down her hair and the prince started climbing immediately, her hair would not break, but it might rip out. Also, the rest of her body might not be able to support the weight. Thankfully, there are strategies that she can use to help reduce the strain on her head and body.

Nathan Harshman, Assistant Professor of Physics at American University in Washington, DC, suggests Rapunzel would be safer and more secure if she tied her hair around something before lowering it. “The whole idea is that you can use the friction of the hair against itself in the knot, and whatever it is tied around will support the weight of the prince.” That is a much better idea than making Rapunzel’s scalp the anchor point.

I’m bummed that the section on The Little Mermaid does not discuss the Hans Christian Andersen original, but rather the Dinsey version (which I admit is a delightful movie, it’s just very Disneyfied.)