course Phy 121 ¨áÒ‡¸¦|î–i£åˆ¿ýœÚ§ãassignment #004
......!!!!!!!!...................................
15:55:02 Intro Prob 6 given init vel, accel, `dt find final vel, dist If initial velocity is v0, acceleration is a and time interval is `dt, then in symbols what are the final velocity vf and the displacement `ds?
......!!!!!!!!...................................
RESPONSE --> `ds = vAve * `dt If v0 = 0, then vf = 2 * vAve. confidence assessment: 3
.................................................
......!!!!!!!!...................................
15:58:42 **You would use accel. and `dt to find `dv: a * `dt = `dv. Adding `dv to initial vel. vo you get final vel. Then average initial vel. and final vel. to get ave. vel.: (v0 + vf) / 2 = ave. vel. You would then multiply ave. vel. and `dt together to get the distance. For example if a = 3 m/s^2, `dt = 5 s and v0 = 3 m/s: 3 m/s^2 * 5 s = 15 m/s = `dv 15 m/s + 3 m/s = 18 m/s = fin. vel. (18 m/s + 3 m/s) / 2 = 10.5 m/s = vAve 10.5 m/s * 5 s = 52.5 m = dist. In more abbreviated form: a * `dt = `dv v0 + `dv = vf (vf + v0) /2 = vAve vAve * `dt = `ds so `ds = (vf + v0) / 2 * `dt. **
......!!!!!!!!...................................
RESPONSE --> Oh, I didn't understand that you only had those values to work with and I just inserted avergae velocity when it wouldn't have been given. I see now how you first have to obtain the change in velocity and then add that to the initial to get the final. Then you have to average the final and initial to get average. Then you can go from tehre to get the displacement. self critique assessment: 2
.................................................
......!!!!!!!!...................................
16:04:51 What is the displacement `ds associated with uniform acceleration from velocity v0 to velocity vf in clock time `dt?
......!!!!!!!!...................................
RESPONSE --> I'm not sure completely what this question is asking. But I think it's asking how you would get displacement and if the acceleration is uniform then you could get the average velocity by adding the initial and final and dividing by 2. Then, since you know the clock time you would multiply the clock time by the average velocity to get displacement. confidence assessment: 2
.................................................
......!!!!!!!!...................................
16:07:24 Describe the flow diagram we obtain for the situation in which we know v0, vf and `dt.
......!!!!!!!!...................................
RESPONSE --> v0 and vf are at top pointing to vAve. From vAve it goes to `ds and then to `dt. confidence assessment: 3
.................................................
......!!!!!!!!...................................
16:10:31 ** The first level in the diagram would contain `dt, v0 and vf. Then v0 and vf would connect to `dv in the second level. The second level would also contain vAve, connected from vf in the first level to v0 in the first level. The third level would contain an a, connected to `dv in the second level and `dt in the first level. The third level would also contain `ds, connected to vAve in the fourth level and `dt in the first level. **
......!!!!!!!!...................................
RESPONSE --> I think this is like the chart I was trying to describe. It's much easier when you use levels to describe them. self critique assessment: 2
.................................................
......!!!!!!!!...................................
16:11:47 Query Add any surprises or insights you experienced as a result of this assignment.
......!!!!!!!!...................................
RESPONSE --> This assignment really helped me distinguish things like average velocity and acceleration and change and velocity and all of those terms. The memorize this sections are really helpful because they sum up the class notes. confidence assessment: 3
.................................................
......!!!!!!!!...................................
16:12:32 ** Student Response: I think I really confused what information stood for what in the Force and Pendulum Experiment. However, I enjoy doing the flow diagrams. They make you think in a different way than you are used to. INSTRUCTOR NOTE: These diagrams are valuable for most people. Not all--it depends on learning style--but most. **
......!!!!!!!!...................................
RESPONSE --> They help me somewhat. It puts on paper the process that I am going through in my head. self critique assessment: 2
.................................................
"