Oscillation (particle movement)

1. The problem statement, all variables and given/known data
A particle rotates counterclockwise in a circle
of radius 4.4 m with a constant angular speed
of 11 rad/s. At t = 0, the particle has an x
coordinate of 2.9 m and y > 0 .
Part 1: Determine the x coordinate of the particle velocity
at t = 1.22 s.
Answer in units of m/s

Part 2: Determine the x coordinate of the particle acceleration
at t = 1.22 s.
Answer in units of m/s2

2. Relevant equations
x = Acos(wt + d)
where d was found in a previous part of the problem and confirmed correct by the program to be:
d = 0.8511870029
v = -wAsin(wt + d); vx = -wRsin(wt) = -vsin(wt)
a = -w2Acos(wt + d)

Note R and A are interchangeable

3. The attempt at a solution
Part 1:
Attempt 1: v = -wAsin(wt + d) = -(4.4 m)sin(11rad/s * 1.22s + 0.8511870029)
v = -4.360544081 m/s
Incorrect
Attempt 2: vx = -wRsin(wt)
vx = -(11rad/s)(4.4m)sin(11 rad/s * 1.22 s) ≈ -36.477666 m/s
vx = -vsin(wt) = (solution from Attempt 1)sin(wt)
vx = -(-4.360544081 m/s)sin(11 rad/s * 1.22 s) ≈ -3.286414681 m/s

Vastly different answers, don’t know if incorrect because I don’t want to get points deducted from score from trying random answers

http://ift.tt/1maA7b4

Leave a comment

Your email address will not be published.


*


Show Buttons
Hide Buttons