Alvarez+lab+15

Preliminary Questions

1. Newton's first law states that the natural tendency for an object is to go in straight path with constant velocity unless a force is acted upon it. Circular motion isnt constant velocity since the vector is changing direction.

2. A change in motion per unit of time is velocity because it is the derivative of position and velocity is the slope on a position vs time graph.

3. the force going towards the center of circular motion is called circular motion.

Table 1.0

 * ** Centripetal Force Data ** ||
 * ** Trial ** || ** Hanging Mass (kg) ** || ** Mass of Stopper (kg) ** || ** Total Time (s) ** || ** Radius (m) ** ||
 * ** 1 ** || 0.10 || 0.12 || 11.87 || 1.0 ||
 * ** 2 ** || 0.15 || 0.12 || 10.23 || 1.0 ||
 * ** 3 ** || 0.20 || 0.12 || 9.86 || 1.0 ||
 * ** 4 ** || 0.25 || 0.12 || 9.62 || 1.0 ||
 * ** 5 ** || 0.30 || 0.12 || 8.15 || 1.0 ||
 * ** 6 ** || 0.35 || 0.12 || 7.77 || 1.0 ||

Lab 2.0

 * ** Centripetal Force Calculations ** ||
 * ** Trial ** || ** Centripetal Force (Fc) (N) ** || ** Period (s) ** || ** Circumference (m) ** || ** Speed (m/s) ** ||
 * ** 1 ** || 1.00 || 0.594 || 6.28 || 10.58 ||
 * ** 2 ** || 1.50 || 0.512 || 6.28 || 12.28 ||
 * ** 3 ** || 2.00 || 0.493 || 6.28 || 12.74 ||
 * ** 4 ** || 2.50 || 0.481 || 6.28 || 13.06 ||
 * ** 5 ** || 3.00 || 0.408 || 6.28 || 15.41 ||
 * ** 6 ** || 3.50 || 0.389 || 6.28 || 16.16 ||

Centripetal Force (N) = weight of hanging mass = hanging mass * 10 N/kg i.e) T1 = 0.01 * 10 = 1 N
 * T1 = trial 1

Periods of Revolutions(s) = total time / 20 revs i.e.) T1 = (11.87) ÷ 20 = .594 s

Circumference (m) = 2 * 3.1416 * radius i.e.) T1 = 2 * 3.1416 * 1 = 6.28 m

Speed (m/s) = circumference / period i.e.) T1= 6.28 ÷ .594 = 10.58 m/s

Analysis: The spinning of the tube provides the centripetal force and the weight on the end helps increase that force. The force is directly towards the center of the tube since the rubber stopper is spinning giving it centripetal force. According to graph 1 as the speed increases so does the force needed to keep the stopper moving around. If we doubled the speed of the revolution we would expect for the centripetal force to quadriple. because it is an exponential graph. We found that as the speed increases the force of centripetal force increases exponentially.

Application: The centripetal force in a car going around a circular off-ramp at constant speed is one the radius of the bend and 2 the turning of the car. If the car went a greater speed and centripetal force than which the road can provide then the car would skid off the road. If the car doubles its speed the centripetal force increase exponentially.