Date
Name
Pd
Lab: Acceleration
Introduction
No Acceleration; a = 0
Observe the motion of the cart after an initial “tap” away from the motion sensor.
What happens to the displacement?
________________________________________________ ___________________________
What happens to the velocity a couple of seconds after the initial “tap”?
_________________________________________________ ____________________________
Is there a change of velocity over time a couple of seconds after the initial “tap”?
____________________________________ ____________________________________
Situation-1: LAB must do: (a-d) and Post-LAB analysis (e- i)
a. Observe the motion of the cart starting from rest (Vo=0) and rolling down the
incline without using the motion detector.
A1.-Record the approximate angle of elevation from the horizontal line with a protractor:
ANGLE θ = _________
A2. -Post-Lab:
Calculate the sine and the cosine of the angle. sin θ = ______
cos θ = ______
A3. –Measure the mass of the cart: Mass = __________ = _______kg
b. Answer the following questions:
B1-What happens to the displacement?
________________________________________________ ___________________________
B2-What happens to the velocity a couple of seconds after the initial “tap”? Magnitude and direction.
_________________________________________________ ____________________________
B3-Is there a change of velocity over time a couple of seconds after the initial “tap”?
Magnitude and direction.
_______________________________________________ ____________________________
Modified by Dr. Vites from ©Modeling Workshop Project 2002
c. Predict the graphs describing the motion over time.
PRACTICE HERE:
FOR Part-d: Use Data Studio.
1. Measure position TWO times.
2. Measure velocity TWO times.
3. Estimate Acceleration from the velocity
graphs.
Remember: slope is
( Δvertical/ Δhorizontal ) = Δv/ Δt
d.-Record the graphs as displayed by the motion
detector.
Comments: see Part-e
POSITION:
a.
b.
c.
VELOCITY:
a.
b.
c.
ACCELERATION:
a.
b.
c.
Modified by Dr. Vites from ©Modeling Workshop Project 2002
e. On each of the observed graphs, describe the slope as:
a) constant, increasing or decreasing
b) positive or negative
c) state what the slope represents
Note: You may have to divide your graph into segments.
f. Determine the equation that describe the graphs
F1.-For V(t) or velocity as a function of time.
Remember:
Y = mX + b
For V
F2.-Use the Graph summary table to determine a general equation that describes displacement as a
function of time or X(t).
For X
F3.-Use the Graph summary table to determine a general equation that describes acceleration as a
function of time or a(t).
For
a
g. Draw a motion map including both velocity and acceleration vectors.
(After you see the Power Point presentation)
G1.- Is the velocity positive or negative? ____________________________
G2.- Is the acceleration positive or negative? ____________________________
h.What is causing the acceleration?
___________________________________ ______________________________
i.Use the data collected in A1 through A3 and explain the value obtained for the acceleration?
Show your work:
Is it close?_________ .
What should it be mathematically? ___________.
What is it in your experimental data? _____________.
FOR DATA STUDIO
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Remember to set-up at 25-30 Hz the rate at which to collect data.
Make sure that probe or detector is facing the object of interest.
Make sure the values make sense. For example the distance traveled cannot be longer that 1.5 meters.
Zoom into the area of interest to make a better recording of slope.
Repeat experiment until it is “clean” on the monitor.
There is a special tool to measure slope- It is useful ONLY IF your data is nice and clean.
Add a couple of hints:
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•
Modified by Dr. Vites from ©Modeling Workshop Project 2002
FORCE DIAGRAM
REMEMBER:
FROM HERE,
Modified by Dr. Vites from ©Modeling Workshop Project 2002
Modified by Dr. Vites from ©Modeling Workshop Project 2002