Quick question (centripetal force)

[rickkwa]

The situation is like this,
You're holding a string with a rock at the end of it. You hold the string above your head and whirl the string. It's going to make an angle with the vertical, so its not 90 degrees.

So if I break it into components,
Ft (tension) * cosX will be the vertical component
Ft * sinX will be the horizontal component

Sigma F = MAc
= (M*V^2) / R

Does this calculate Ft or Ft*sinX (horizontal component)?

 

[Apphysicist]

Only Ft*sinX. In the horizontal circle (draw it in, why not?), the only component of your forces is the horizontal component of tension. Assuming it is not falling or moving up, the vertical component of tension balances with gravity.

 

[ashishsinghal]

Totally agree with Apphysicist