Question

Hi, I did a lab on ROTATIONAL KINEMATICS and I'm having a little trouble answering the questions at the end of the lab.

For this lab, we used an object attach to a parallel shaft that spins. There was a hanging mass attached to the shaft that made the object spin. We then recorded the times for two different methods. These methods were PART A). Angular Position Versus Time, and PART B). Angular Velocity versus Time.

Once done, we were to answer:

1 It was stated in step B-4 that the speed of the hanging strip as it passes through the photogate is given by v = x/T. Why is that so?

2. Which curve, the one graphed in Part A or the one graphed in Part B, gives a better value for the angular acceleration? Explain why this is so.

3. you have made four seperate determinations of the angular acceleration; how do they compare? Which do you think is the most accurate? Explain why this is so.

If anyone could please help me with these 3 quesiton. That would be great. If you need anymore information about my lab to answer these question, just let me know. I would be more than happy to provide.

Answer 1

1. the hanging strip moves in a linear motion , hence we the linear speed is given as

linear speed = linear distance / time taken = x /T

2. the graph drawn in part B gives better value for angular acceleration since slope of angular velocity - time curve gives angular acceleration according to the formula

angular acceleration = change in angular velocity / time taken

3. i need more information about the lab for this problem. regarding determination of four sepeate angular acceleration.