A child stands on the edge of a merry-go-round

[joe426]

Homework Statement

A 15 kg child stands on the edge of a small merry-go-round of radius 2.0 m. If the merry-go-round turns at a steady rate of 11 rpm, calculate the magnitude and direction of the net force
on the child.

Homework Equations

I'm thinking F_G = G(m/r²)

The Attempt at a Solution

F_G = 11(15/2^2)
= 41.25

The direction would be clockwise?

 

[Nytik]

For circular motion, F = mrω^2

ω = 2π/T where T is the time period for one rotation.

Also, the force in circular motion always points in a particular direction. Do you know it?

 

[joe426]

For circular motion, F = mrω^2

ω = 2π/T where T is the time period for one rotation.

Also, the force in circular motion always points in a particular direction. Do you know it?

So it would be,

F= (15)(2)(2π/11)^2
F= 9.7N

The force in circular motion always points towards the center or rotation.

 

[Nytik]

Almost, but you have to convert your value for T into the correct units first. It might be easier to use ω = 2πf, where frequency is revolutions per second.

 

[joe426]

almost, but you have to convert your value for t into the correct units first. It might be easier to use ω = 2πf, where frequency is revolutions per second.

f= (15)(2)(2π(11/60))^2
f= 30 * (2π * .183)^2
f= 34n

 

[Nytik]

The equation is correct but I think you forgot to square the bracket.

 

[joe426]

The equation is correct but I think you forgot to square the bracket.

Oops.

correct answer is 39N.


Thanks for your help!