Week of the experiment: 4
OBJECTIVE (3 points):
The objective of this lab is to gain a more complete conceptual understanding of 2-D kinematics. We will explore the concepts of position, distance, velocity, and displacement through the use of the motion data gathered with a cart simulation. This will be used to extrapolate and calculate graphs and equations for the positions and velocity.
EXPERIMENTAL DATA (3 points):
PART 1: Object moving away from the motion sensor.
Table 1
|
Run # |
Time interval, (s) |
Position (m) [Initial & End] |
Distance (m) |
Displacement (m) |
Speed (m/s) |
Velocity (m/s) |
|
1a |
8.187 to 9.843 |
0.85 to 1.70 |
0.850 |
0.850 |
0.513 |
0.513 |
|
1b |
7.09 to 8.06 |
0.28 to 0.78 |
0.500 |
0.500 |
0.515 |
0.515 |
|
1c |
9.281 to 10.06 |
1.41 to 1.81 |
0.400 |
0.400 |
0.513 |
0.513 |
Table 2
|
Run # |
Slope (m/s) |
Y-intercept (m) |
Name of Physics quantity (i.e. position, distance, etc.) |
|
1 |
0.5160 +/- 0.0001203 |
-3.376 +/- 0.001031 |
Position |
|
2 |
1.645 +/- 0.0001288 |
-1.982 +/-0.0002569 |
Position |
Using equation 5, substitute in your slope and y-intercept to create an equation that describes the motion of the cart:
Run 1_y=0.5160x -3.376
Run 2: y=-0.00260x+0.5383
Table 3. (Use Logger Pro for statistical data to calculate avg. velocity and uncertainty)
|
Run # |
Average Velocity, (m/s) |
Standard deviation (m) |
|
1 |
0.5162 |
0.002718 |
|
2 |
1.661 |
0.002959 |
PART 2: Object moving toward the motion sensor.
Table 4
|
Run # |
Slope (m/s) |
Y-intercept (m/s) |
Name of Physics quantity (i.e. position, distance, speed, etc.) |
|
3 |
-.8242, +/- .0001528 |
3.108, +/- .0004052 |
Position |
|
4 |
-1.235 +/- .0002127 |
7.175 +/- .001075 |
Position |
Using equation 5, substitute in your slope and y-intercept to create an equation that describes the motion of the cart:
Run 3: Position = -.8242t + 3.108
Run 4: Position = -1.235t + 7.175
Table 5. (Use Logger Pro for statistical data to calculate avg. velocity and uncertainty)
|
Run # |
Average Velocity, (m/s) |
Standard deviation (m/s) |
|
3 |
-.8370 +/- .002111 |
.002778 |
|
4 |
-1.275 +/- .01070 |
.003428 |
PART 3. Matching position vs. time graphs
Run 5: Include in the Discussion the methods used to reproduce the graph.
Insert the best match for the position vs time graph.
DATA ANALYSIS (10 points): the section includes equations, calculations and error analysis if required. Be sure all equations are present!
PART 1 & 2:
Show the equation with the plugged in numbers you used in run 1 to calculate the cart’s:
·Distance: xFinal – xInitial = Distance traveled
1.70 m – .85 m = .85 m
(
·Displacement: xFinal – xInitial = Displacement
1.70 m – .85 m = .85 m
·Average speed: Displacement / Time = Average speed
.85 m / (9.843 – 8.187) s = .513 m/s
·Average velocity: Displacement / Time = Average velocity
.85 m / (9.843 – 8.187) s = .513 m/s
For run 2 and 4, calculate the percent difference between the average velocity from the slope of the x(t) graph and mean velocity from v(t) graph.
Let x=slope of x(t) & v=mean velocity of v(t)
% Difference = 100 * |x+v|/((x+v)/2)
Run #2: 100 * |.516+.5162|/((.516+.5162)/2) = 0.0387%
Run #4: 100 * |-1.235+-1.275|/((-1.235+-1.275)/2) = 3.187%
PART 4:
Run 6: Show calculation (use eqn. 5) used to make a prediction for the final position of the cart after 2 s from the moment it crosses the 80 cm mark on the track.
x(t) = x0 + v(t-t0)
x(t)= (80cm) + (-20m/s)(2s-0s)
x(t)=80cm +(-40cm)
x(t)=40cm
RESULTS (3 points):
Table 6. PARTS 1 & 2 (Report results below with 4 significant figures)
|
Average velocity (m/s) |
|||
|
Run # |
Position vs. Time graph |
Velocity vs. Time graph |
% Difference |
|
1 |
.516 |
.5162 |
0.0387% |
|
2 |
1.645 |
1.661 |
0.9679% |
|
3 |
-.8242 |
-.8370 |
1.541% |
|
4 |
-1.235 |
-1.275 |
3.187% |
Table 7. PARTS 1 & 2 Equations of motion
|
Run # |
Substituted Equations of Motion (equation 5) |
|
1 |
x(t) = x0 + .5162(t-t0) |
|
2 |
x(t) = x0 + 1.661(t-t0) |
|
3 |
x(t) = x0 + -.8370(t-t0) |
|
4 |
x(t) = x0 + -1.275(t-t0) |
Table 8. PART 4 final position of cart after 2 s
|
Predicted position: |
Experimental position: |
|
40.0cm |
40.7cm |
DISCUSSION AND CONCLUSION (10 points):


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