Acceleration on an Inclined Track
Flora Lee (with Amani Broyles and You-shin Kim)
Physics Block 2
Mr. Elwer
Introduction
-Background information
In Distance versus time graph, the slope means a velocity. And the Velocity versus time graph the slope means acceleration. So if the velocity and time graph increases in a straight line, it has a constant acceleration, because the velocity which means speed changes constantly.
-Purpose of the experiment
To find out the relationship among position, velocity and acceleration for linear, we will use Motion sensor, Xplorere GLX and the cart.
-What concept is being explored or investigated
The concept, that direction or magnitude of acceleration and velocity, depending on velocity and position, will be investigated through experiment.
-Hypothesis
The position graph of the cart will decrease first and increase again as it getting closer to the cart and sliding back. The velocity graph will be negative at first and then become positive. And the acceleration of the graph will be constant since the change of velocity is constant.
Materials
-Motion Sensor , GLX , plane and cart, the track for cart, and the book to make track inclined.
Experimental Design
We will set the track inclined, and we will put the censor on the top. After we set up GLX and other tools, we will push the cart forward the hill that we made by book. The car will slide down back. The censor will recognize the speed and position, and the graph will be shown automatically.
Independent variable: As we push the cart to the top of the track, the displacement will be changed. Thus the position will decrease as the cart go near the censor, and it increase as the cart go back to his position. But we are not looking for the difference between the products which has two different displacement, it cannot be a independent.
Dependent: As the position of the cart is changed, the velocity and acceleration is changed too following its original function, position.
Control: Since we are human being, we cannot push the cart with same force every time. So it can be changeable. Also the angle of the road or how big the frictions are, is chageable too.
Procedure
1. Connect the GLX and motion sensor
2. Turn on the GLX
3. Push the button Graph‘
4. Make a inclined road for car by using books and track(pasco).
5. Place the cart facing the sensor.
6. Check the sensor if it reflect the cart.
7. Press Start (play) button to record the graph of cart.
8. Push the same button to end recording.
9. Press check mark button2 times.
10. Choose the ‘more’ button.
11. Then you can chose velocity or acceleration.
12. Press F3and chose Linear Fit.
13. Press Check button 3 times
14. Select the region.
15. Press ceck to open tools.
16.Record average value acceleration in the lab report.
Data table
Data table
Item | Value |
Acceleration (slope) | 0.782±0.187 m/s^2 |
Acceleration (avg) | 0.55 m/s^2 |
Graph
Position-Time Graph(m-s)
Velocity-time Graph(m/s-s) 
The position graph we got makes a concave up graph which is decreasing first and then increasing. As we see the slope of position graph, we can think abou the velosity. velosity starts from the negative point since the position graph was decreasing at first. But velocity becomes positive later as the poesition graph was increasing. The slope of the velocity-time graph increases constantly. So the acceleration was constant. From this experiment we can see the relatioship betwwen position, velocity and acceleration. Because the slope of former graph is realated to next graph. My hypothesis is almost correct. velocity changed from negative to positive and the acceleration is constante. The error we got was unperfect graph. It is not clearly smooth because the sesor reflected other small things too, not only cart. And sometimes the cart hit the sensor so it influence to speed. To improve this, we need to be more careful when we do experiment.
1. Describe the position versus time plot of the Graph screen. Why does the distance begin at a maximum and decrease as the cart moves up the inclined plane?
The position in this experiment is the distance between sensor and the cart. The reason it begins at a maximum is, it was farder when the cart start to run. and it gets closer as it goes up(get closer to sensor)
.
2. Describe the velocity versus time plot
As the time pass, the velocity increase. And we can know that the rate of increasing is constant becuase it is a straight line.
3. Describe the acceleration versus time plot of the Graph display
The acceleration is almost constant. it is straight line which does not go up or down.
4. How does the acceleration determined in the plot of velocity compare to the average value of acceleration fromthe plot of acceleration.
SInce the slope of velocity means acceleration, it is almost same value with average value of acceleration. Because average value of acceleration will be (Vf-Vi)/(Tf-Ti).
