#$&*
course Phy 201
Questions:1. What was your count for the pendulum bouncing off the bracket, and how many seconds did this take? What therefore is the time in seconds between collisions with the bracket? What was the length of your pendulum?
-32 beats on the pendulum, in 16seconds
-2 seconds every beat of a pednulum
If every beat took two seconds then 32 beats would take 64 seconds, not 16 seconds.
There were two beats every second, so the time between beats was 1/2 second.
-5 ½ cm
2. What was the period of your pendulum when it was swinging freely? Give your data and briefly explain how you used it to find the period. How does your result compare with the time between 'hits' in the first question?
1 Domino, 43 full Cycles
1 Domino, 37 full Cycles
1 Domino, 42 Full Cycles
Had the pendulum on 1 domino had it swing freely for 30 seconds. These results are much less than the first one because the pendulum is swinging freely.
3. Give your data for the ball rolling down the ramp, using the bracket pendulum as your timer. Assuming the ball traveled 30 cm each time, what are the resulting average velocities of the ball for each number of dominoes?
1 domino, 6 beats, 6 beats, 5 beats, Average Velocity=.2
2 domino, 4 beats, 4 beats, 4 beats, Average Velocity=.13
3 domino, 3 beats, 3 beats, 3 beats, Average Velocity=.1
4. How did your results change when you allowed the ball to fall to the floor? What do you conclude about the time required for the ball to fall to the floor?
1 domino, 8 beats, 7 beats, 7 beats
2 domino, 5 beats, 5 beats, 5 beats
3 domino, 4 beats, 4 beats, 5 beats
Its looks like according to my data it takes an extra beat to hit the floor which means it takes an extra 2 seconds.
That would be an extra 1/2 second.
5. Look at the marks made on the paper during the last class, when the ball rolled off the ramp and onto the paper. Assuming that the ball required the same time to reach the floor in each case (which is nearly but not quite the case), did the ball's end-of-ramp speed increase by more as a result of the second added domino, or as a result of the third? Explain.
The Ball’s end of ramp speed increased by more as a result of the third added domino, because with three dominos the ball is coming off the ramp much faster as you can tell in my previous experience the beats are two seconds faster.
Your answer doesn't appear to be related to the marks on the paper. That should be the basis for your conclusions.
6. A ball rolls from rest down a ramp. Place the following in order: v0, vf, vAve, `dv, v_mid_t and v_mid_x, where the quantities describe various aspects of the velocity of the ball. Specifically:
* v0 is the initial velocity,
* vf the final velocity,
* vAve the average velocity,
* `dv the change in velocity,
* v_mid_t the velocity at the halfway time (the clock time halfway between release and the end of the interval) and
* v_mid_x the velocity when the ball is midway between one end of the ramp and the other.
Explain your reasoning.
V0, v mid t, v mid x, Vf, vave, ‘dv
You must start with the Initial, , the next one halfway time, the the midway point, then final velocity, Then with all the information you can get the average velocity, and with average velocity you can get the change in velocity.
If a ball rolls from rest down a ramp and achieves a velocity of 20 cm/s at the end, then what are its initial, average and final velocities, and what is the change in its velocity?
Compare the order of these quantities with the order you gave.
7. A ball rolls from one ramp to another, then down the second ramp, as demonstrated in class. Place the following in order, assuming that v0 is relatively small: v0, vf, vAve, `dv, v_mid_t and v_mid_x .
Place the same quantities in order assuming that v0 is relatively large.
Which of these quantities will larger when v0 gets larger? Which will get smaller when v0 gets larger? Which will be unchanged if v0 gets larger?
-v0, vf, vAve, ‘dv, v mid t, v mid x
-v0, vf, vAve, ‘dv, v mid t, v mid x
-v0, vf, vAve, ‘dv, v mid t, v mid x
8. If a ball requires 1.2 seconds to travel 30 cm down the ramp from rest:
* What is its average velocity?
30cm/1.2sec=25cm/sec
* What is its final velocity?
25cm/s
The ball starts from rest, so its final velocity will be different than its average velocity.
* What is the average rate of change of its velocity?
25cm/s
Be sure to explain your reasoning.
&#This looks good. See my notes. Let me know if you have any questions. &#