Maximum velocity for a piston in simple harmonic motion.

[Runaway]

Homework Statement

A piston in an automobile engine is in simple
harmonic motion. Its amplitude of oscillation
from the equilibrium (centered) position is
±6.87 cm and its mass is 1.472 kg.
Find the maximum velocity of the piston
when the auto engine is running at the rate of
3220 rev/min.
Answer in units of m/s.

Homework Equations

Vt = - w A sin(wt)
w = (2 pi)/T
A = amplitude
T= period
t=time point

The Attempt at a Solution

I tried using graphing -2 Pi/(1/3220) * 0.0687m sin ((2pi/(1/3220)*t) (with x substituted in for t), then finding the maximum on my calculator, and I got 1390, which my online assignment says is the wrong answer.

 

[collinsmark]

I tried using graphing -2 Pi/(1/3220) * 0.0687m sin ((2pi/(1/3220)*t) (with x substituted in for t), then finding the maximum on my calculator, and I got 1390, which my online assignment says is the wrong answer.

The given angular speed is 3220 rev/min.

But are you trying to calculate the velocity in meters per minute, or meters per second? If its m/s (as the problem statement directs you to express your answer), you'll need to convert from minutes to seconds somewhere.

 

[Runaway]

I feel really stupid right about now... thanks for the help though. :)