Determine the components of force

[joemama69]

Homework Statement

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

Homework 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)

The Attempt at a Solution

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

 

[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?

 

[joemama69]

ya lost me, please elaborate

 

[Astronuc]

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.