E-6

CALCULATION

1. Calculate R:

   Measure "R" with the weight attached, make sure that the pointer's position agrees with the one while the rotor is rotating. You have four measurements for R, two from you and two from your partner. Calculate the mean and sR from these values

2. At each spring setting, use equation w = 2pn/Dt to calculate the angular speed. You have four values for Dt, two of yours, and two of your partner's.(use mean value of Dt)
3. Attention: use Z-equation to calculate the standard deviation of w (for each spring setting)
4. At each spring setting, use equation F = mw²R to calculate the centripetal force. Use mean value of w and R. m is the mass of the cylinder.
5. F is the force supplied by the spring. F = (m_added + m)g, where m is the mass of the cylinder. Calculate s_F by multiplying the mass uncertainty by g, where the mass uncertainty is the uncertainty of the added weight. you can obtain this uncertainty by adding or substracting a bit of load until the pointer is discernibly away from the index.

Error analysis
Use equation s_mw²R²/(mw²R)² = s_R²/R² + 4s_w²/w² to evaluate the error of the force.
where w is more important because it is multiplied by a factor 4.