What is the Relationship Between Force and Weight?

[Northern Cardinal]

Homework Statement

I need help figuring out c.

a) A 15.0-kg child is riding a playground merry-go-round that is rotating at 45.0 rpm. What centripetal force must she exert to stay on if she is 1.50 m from its center?
Correct answer: 499.649 N
b) What centripetal force does she need to stay on an amusement park merry-go-round that rotates at 3.00 rpm if she is 7.10 m from its center?
Correct answer: 10.511 N
c) Compare each force with her weight.

Relevant Equations

force from part (a) / weight = _______
force from part (b) / weight = _______

So here's what I've tried:

force from part (a) / weight = 499.649N / 15kg = 33.310
force from part (b) / weight = 10.511N / 15kg = 0.701

Apparently this wasn't correct. What am I doing wrong? I feel like I'm missing the obvious.

 

[gneill]

Mass is stated in kg. That's not weight. Weight is a force in Newtons.

 

[Northern Cardinal]

Thanks! I was able to figure out the correct answer.

 

[gneill]

Excellent!