Answer:

Explanation:
Here as we know that total angular momentum is always conserved for child + round system
so here by angular momentum conservation we have

here we have
(inertia of boy)


now we have




Answer:
counter question if you get out the shower clean then how does your towel get dirty?
C I’m not that sure though
Explanation:
By Hooke's Law,
F=kx
The only force acting here is weight, and x is the extension of the string (you need to convert this to mm) so
mg=kx
(0.15)(9.81)=k ((420-300)x10^-3)
Then just solve this equation.
Can you please stop pasting this question, just go to his profile and ask him.