Acceleration Lab
The purpose of this activity is to determine the velocity and acceleration of a cart rolling
down a track. You will also need to compare your acceleration results to theoretical
values (to check if the physics is working!). Here is what you will be assessed on:
1.8 The ability to synthesize, analyse, interpret, and evaluate qualitative and/or quantitative data to
determine whether the evidence supports or refutes the initial prediction or hypothesis and whether it is
consistent with scientific theory; identify sources of bias and/or error; and suggest improvements to the
inquiry to reduce the likelihood of error.
To carry out this investigation you will use a motion sensor and a cart on a track.
1. Set up a ramp with the cart going down and determine the angle of the ramp
relative to the horizontal. Draw a sketch and show your ramp and show your
calculations here:
The angle θ of my ramp is: ________________
HYPOTHESIS: The theoretical value of what the acceleration should be can be
determined with the following equation: a(on a ramp) = sinθ * 9.8m/s2 .
Find the theoretical value of acceleration and show your work below:
The cart should accelerate at ___________ based on the theoretical value above.
2. In the first part of this investigation you will release a cart at the top of the track
and graph its POSITION as it rolls down the track using your GLX. Before you
actually collect data, predict what the position time graph will look like by
sketching it in the space available below. Label the sketch “Prediction of
Position – down ramp”
3. Use the GLX to collect data while the cart rolls down the incline. Try to start the
GLX as soon as you release the cart and stop the collection just as the car reaches
the bottom of the incline. If you are not successful the first time, try again. When
you have been successful in collecting the data, copy your data into the graph
above and label it ACTUAL POSITION DATA. Describe the motion of the
cart here (tell the story).
4.
Use the tangent tool on your GLX to
determine the highest velocity
reached by the cart (remember, velocity is the slope of a d vs t graph). Record it
in the space below.
vmax=_________________________________
5. Why did you use a tangent to find velocity on this
graph??___________________________________________________________.
SAVE YOUR DATA AT THIS POINT
6. Set up your GLX to collect both d-t and v-t on two graphs shown in the same
screen. Repeat step 3. Sketch your data below.
7. What does the shape of the velocity time graph tell you about the acceleration?
(ie. Is the acceleration constant or not constant? Explain using the results of your
graph and using the language of physics.)
8. Acceleration is defined as a = v/t. a = v/t is simply the slope of the
velocity time graph above.
Use the smart tool
on your GLX to find 2 points on your velocity vs
time graph. In the space below, write your two points down and then determine
the slope of the portion of the graph, which represents the acceleration.
What is the value of the acceleration? a = __________________________
9. What if you were to make the incline steeper of your ramp steeper, how do you
think the graph would change? Why would it do this? (Hint: if the angle of the
ramp was 90 degree (ie straight down), what would be the value of the
acceleration?).
10. State your results: The acceleration of the cart on the ramp is: ____________.
12. Find the % error between your actual results and what the theoretical results should
be. Show your work in the space below.
13. Account for any sources of error and EXPLAIN HOW YOU WOULD IMPROVE
THE EXPERIMENT TO REDUCE THE ERROR.