Cylindrical coordinates

1. Apr 8, 2009

joemama69

1. The problem statement, all variables and given/known data
the boy of mass 40kg is sliding down the spiral slide at a constant speed such that his position, measured from the top of the chute, has components r=1.5m, theta=.7t radians, and z = -.5t m, where t is in seconds. Determine the components of force for F(r), F(theta), and F(z) which the slides exerts on him at the instant t=2. Neglect the size of the boy

2. Relevant equations

a(r)=r''-r(theta)'^2 F(r)=ma(r)
a(theta)=r(theta)''+2r'(theta)' F(theta)=ma(theta)
a(z)=z'' F(z)=ma(z)

3. The attempt at a solution

I got F(r)=-29.4 N and I got 0 for the other 2 Forces. Is this corect

2. Apr 8, 2009

LowlyPion

In the way you have answered it, I'd say it looks correct.

But the question seems to ask for the components "for" these forces, and I am not sure that they don't want the components ... you know like the friction force offsetting the acceleration effects from gravity?

3. Apr 8, 2009

joemama69

ya lost me, please elaborate

4. Apr 8, 2009

Staff: Mentor

The boy is sliding down the spiral slide at a constant speed, and r is constant.

Don't forget the boy has weight acting downward.

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook