- #1
1v1Dota2RightMeow
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- 7
Homework Statement
A small bead of mass m is constrained to move on a helix: r (θ) = (R cos(θ), R sin(θ), q θ) where R and q are constants, and θ=θ(t) describes the position of the bead along the helix at time t. The bead is also subjected to a gravitational acceleration g downward (-z direction). Find the following quantities in terms of θ and dθ/dt.
c) The potential energy U
Homework Equations
r (θ) = (R cos(θ), R sin(θ), q θ)
θ=θ(t)
The Attempt at a Solution
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I'm only asking because my attempt at a solution proved to be so simple that I'm a bit nervous about it. If I define the position vector (given above) to have coordinates (x,y,z) and claim that as the particle moves in an upwards (+z) directed helical path, then the potential energy is entirely due to gravity and therefore it is U=mg(qθ). Although I'm not sure if I might have missed something...