Question

What happens to the angular speed of a rotating merry go round if a child on the merry go round leaves the horse on the outer edge and moves to the cow near the center of the merry go round?

a) it increases

b) it decreases

c) it stays the same

d) impossile to determine

Answer 1

moment of inertia , I= m*r^2

since r decreases , I decreases

angular momentum = I*omega

to keep angular momentum constant [ under no external torque],

angular velocity increases

Answer 2

a) it increases

Answer 3

Angular momentum is conserved
That is I*w is constant.
Where I is moment of Inertia and w is angular speed
When child get closer to center, I decreases and hence w increases.

Ans:A

Answer 4

L=Angular moment should be conserved= Iw should be constant

I proportional to m

so if I decrease(as m decreases) , w should increase to keep L as constant

answer : a) it increase

Answer 5