This experiment aims to measure the acceleration due to gravity, g, by investigating the free fall motion of steel balls with air resistance. The time taken for a ball to fall between two points a known distance apart is measured using a ticker timer. By plotting distance against time squared on a graph, the gradient gives the value of g. Sources of error include the ticker timer ticking at fixed intervals, air resistance, human error in measurement and ensuring the balls are dropped from the same height.
Physical Quantities--Units and Measurement--Conversion of UnitsKhanSaif2
This presentation covers physical quantities and their types, units and their types, conversion of units and order of magnitude in a very interactive manner. I hope this presentation will be helpful for teachers as well as students.
Physical Quantities--Units and Measurement--Conversion of UnitsKhanSaif2
This presentation covers physical quantities and their types, units and their types, conversion of units and order of magnitude in a very interactive manner. I hope this presentation will be helpful for teachers as well as students.
The presentation covers, Dimensions and standards, SI Unit system, Definition of basic units, SI Temperature Scale, Other Unit System, Non SI Units in common Uses, Scientific Notations, Prefixes, Significant figures
The presentation covers, Dimensions and standards, SI Unit system, Definition of basic units, SI Temperature Scale, Other Unit System, Non SI Units in common Uses, Scientific Notations, Prefixes, Significant figures
2048L/Lab 2/Lab Manual 2 c.pdf
1
Lab Manual
Irina Golub
July 30, 2017
2
PART ONE: Photographic Analysis of a Falling Object
INTRODUCTION
With the great advances that have been made in digital imaging and analysis, experimental data
is often in the form of photographic images. In this experiment, you will make displacement
measurements of a tennis ball dropped from a height using photographic data and your
computer’s mouse positioning system. From two displacement measurements and the time
between these measurements and one of the five kinematic equations that describe one-
dimensional motion, the acceleration due to gravity on earth, “g”, will be estimated. Since you
know what the correct answer should be (9.8 m/s2) you will be able to calculate the percent
error of your estimate.
Neglecting air resistance, a falling object increases its speed 9.8 meters per second every
second that it falls on earth. This is “g”, the acceleration due to gravity. Below you will see
snapshots taken of a falling tennis ball at equal intervals of time (0.1 second between frames).
You can see that the displacement of the tennis ball increases during each successive time
interval. This is due to the tennis ball speeding up in each time interval, i.e., the tennis ball is
accelerating.
Read University Physics Volume 1 Chapter # 3: MOTION ALONG A
STRAIGHT LINE
EQUIPMENT
A PC running MS Internet Explorer web browser. (Other web browsers may not work for
this experiment.)
OVERVIEW
The photographic data file shows one composite photo made by splicing six separate images
of a tennis ball dropped straight down. Each of the six separate images was taken 0.1 second
apart.
Just below the photo in the photographic data file you will see boxes labelled X and Y with
numbers that change when you move the mouse over the photo. These numbers are mouse
coordinates in what we will call “mouse units.”
You will record the Y-position of the ball in the first and last image (i.e., ball image #1
and ball image #6) (the X-direction is not needed as the object was falling straight down).
Since the numbers you record will be in mouse units and not meters, only the difference
between these two measurements will be important. You will be able to convert this
difference from mouse units into meters because there are two meter sticks joined together
vertically in each photo as a reference.
[If you are unable to see the mouse coordinates in your browser and are un- able to get to
a BCC lab computer you can measure ruler coordinates instead of mouse coordinates using
a plastic ruler held near (but not touching!) the computer display. Substitute the phrase ”ruler
coordinates” for ”mouse coordinates” in the procedure and questions. Take your
measurements in millimeters. This will not be as accurate as using mouse coordinates which
have a higher resolutio.
A method for determining a physical law using the simple pendu.docxransayo
A method for determining a physical law using the simple pendulum as a model
By
name
Lab Partner: name
7 September 2000
Abstract
A process for determining a physical law was executed using the simple pendulum as a
model. The three variables thought most likely to be major influences on pendulum
period were selected. Each variable was tested while holding the others constant.
Displacement affected period, but for displacements less than 10 degrees string length
had the most significant effect on period. The law relating period to string length was
determined. The experimental law did not agree with the accepted law within
experimental uncertainty.
! 1
INTRODUCTION AND THEORY
The simple pendulum system was selected to test a method for determining physical
laws. The method was applied to determine which variables influence the period of the
pendulum. The goal was to derive the law that relates the period of the pendulum to the
most significant variables. A diagram of the simple pendulum is shown in Figure 1.
{Note that I have called out the figure in the text before the figure appears.}
!
Figure 1. Diagram of the simple
pendulum. θ is the displacement angle, L is the
length of the pendulum, g is the acceleration due to
gravity, m is the mass of the pendulum bob, and T is
the tension in the string. {Note: This is Figure 1,
not Figure 1.1. Number your figures and tables
sequentially as they appear in the text. This is a
! 2
stand-alone report, not a report in a sequence of
reports in lab.}
Operational definition of period: Time for pendulum to go from any point
in its motion back to that same point, and traveling in the same direction.
Table 1. is a list of equipment used in the experiment. {Table mentioned
in text before it appears.} {I have taken care to see that the table is all
on one page and does not flow to a second page.}
Table 1. Equipment Used.
Experimental support rod clamped to lab bench
Experimental support arm fastened to support rod
String
Clamped on the experimental support arm
~ 1.1 m long
There was a loop at one end
Pendulum bobs
Six different materials: cork, wood, steel, lead, aluminum, and brass
All bobs had hooks to which the loop in the string was attached
All bobs were the same size as observed by eye
Meter stick
Protractor
PASCO Photogate operating in pendulum mode
PASCO Model 500 Interface
! 3
Pentium computer running Windows NT
Science Workshop Software
Microsoft Excel
{table 1 is where you describe the equipment was used. This is not the place to tell how
it was used. That goes in the experimental procedure in the text.}
DESCRIPTION OF THE EXPERIMENT DATA AND ANALYSIS
Note to students. The nature of this experiment does not lend itself to following
the FORMAT I specified in my e-mail guidance and on my web site. For the formal
reports, use the guidance on the web.
Experiment5Physics with Calculators 5 - 1Picket Fe.docxgitagrimston
Experiment
5
Physics with Calculators 5 - 1
Picket Fence Free Fall
We say an object is in free fall when the only force acting on it is the earth’s gravitational force.
No other forces can be acting; in particular, air resistance must be either absent or so small as to
be ignored. When the object in free fall is near the surface of the earth, the gravitational force on
it is nearly constant. As a result, an object in free fall accelerates downward at a constant rate.
This acceleration is usually represented with the symbol g.
Physics students measure the acceleration due to gravity using a wide variety of timing methods.
In this experiment, you will have the advantage of using a very precise timer connected to the
calculator and a Photogate. The Photogate has a beam of infrared light that travels from one side
to the other. It can detect whenever this beam is blocked. You will drop a piece of clear plastic
with evenly spaced black bars on it, called a Picket Fence. As the Picket Fence passes through
the Photogate, the LabPro or CBL 2 interface will measure the time from the leading edge of one
bar blocking the beam until the leading edge of the next bar blocks the beam. This timing
continues as all eight bars pass through the Photogate. From these measured times, the program
will calculate the velocities and accelerations for this motion and graphs will be plotted.
Picket
fence
Figure 1
OBJECTIVE
• Measure the acceleration of a freely falling body (g) to better than 0.5% precision using a
Picket Fence and a Photogate.
MATERIALS
LabPro or CBL 2 interface Vernier Photogate
TI Graphing Calculator Picket Fence
DataGate program clamp or ring stand to secure Photogate
Modified from and reported with permission
of the publisher Copyright (2000),
Vernier Software & Technology
Experiment 5
5 - 2 Physics with Calculators
PRELIMINARY QUESTIONS
1. Inspect your Picket Fence. You will be dropping it through a Photogate to measure g. The
distance, measured from one edge of a black band to the same edge of the next band, is
5.0 cm. What additional information will you need to determine the average speed of the
Picket Fence as it moves through the Photogate?
2. If an object is moving with constant acceleration, what is the shape of its velocity vs. time
graph?
3. Does the initial velocity of an object have anything to do with its acceleration? For example,
compared to dropping an object, if you throw it downward would the acceleration be
different after you released it?
PROCEDURE
1. Fasten the Photogate rigidly to a ring stand so the arms extend horizontally, as shown in
Figure 1. The entire length of the Picket Fence must be able to fall freely through the
Photogate. To avoid damaging the Picket Fence, make sure it has a soft landing surface.
2. Connect the Photogate to the DIG/SONIC 1 input of the LabPro or the DIG/SONIC input on the
CBL 2. Use the black link cable to connect the interface to the TI Graphing Calculator.
Firmly pr ...
11 - 3
Experiment 11
Simple Harmonic Motion
Questions
How are swinging pendulums and masses on springs related? Why are these types of
problems so important in Physics? What is a spring’s force constant and how can you measure
it? What is linear regression? How do you use graphs to ascertain physical meaning from
equations? Again, how do you compare two numbers, which have errors?
Note: This week all students must write a very brief lab report during the lab period. It is
due at the end of the period. The explanation of the equations used, the introduction and the
conclusion are not necessary this week. The discussion section can be as little as three sentences
commenting on whether the two measurements of the spring constant are equivalent given the
propagated errors. This mini-lab report will be graded out of 50 points
Concept
When an object (of mass m) is suspended from the end of a spring, the spring will stretch
a distance x and the mass will come to equilibrium when the tension F in the spring balances the
weight of the body, when F = - kx = mg. This is known as Hooke's Law. k is the force constant
of the spring, and its units are Newtons / meter. This is the basis for Part 1.
In Part 2 the object hanging from the spring is allowed to oscillate after being displaced
down from its equilibrium position a distance -x. In this situation, Newton's Second Law gives
for the acceleration of the mass:
Fnet = m a or
The force of gravity can be omitted from this analysis because it only serves to move the
equilibrium position and doesn’t affect the oscillations. Acceleration is the second time-
derivative of x, so this last equation is a differential equation.
To solve: we make an educated guess:
Here A and w are constants yet to be determined. At t = 0 this solution gives x(t=0) = A,
which indicates that A is the initial distance the spring stretches before it oscillates. If friction is
negligible, the mass will continue to oscillate with amplitude A. Now, does this guess actually
solve the (differential) equation? A second time-derivative gives:
Comparing this equation to the original differential equation, the correct solution was
chosen if w2 = k / m. To understand w, consider the first derivative of the solution:
−kx = ma
a = −
k
m
⎛
⎝
⎜⎜⎜⎜
⎞
⎠
⎟⎟⎟⎟
x
d 2x
dt 2
= −
k
m
x x(t) = A cos(ωt)
d 2x(t)
dt 2
= −Aω2 cos(ωt) = −ω2x(t)
James Gering
Florida Institute of Technology
11 - 4
Integrating gives
We assume the object completes one oscillation in a certain period of time, T. This helps
set the limits of integration. Initially, we pull the object a distance A from equilibrium and
release it. So at t = 0 and x = A. (one.
PHYS 221Lab 1 - Acceleration Due to GravityPlease work in g.docxmattjtoni51554
PHYS 221 Lab 1 - Acceleration Due to Gravity
Please work in groups of three. Please submit one lab report per person via Canvas.
In this laboratory we will measure the acceleration due to gravity by studying the motion of a cart accelerating down an inclined plane.
Background
Suppose we start with a level track and then tip it, as shown in Figure 1 below. Let L be the distance between two fixed points on a ramp, selected to be as far apart as possible, on the track. Let h be the difference in the vertical height above the table of these two points.
Figure 1 - Schematic of a cart on an inclined plane. The magnitude of the acceleration of the cart down the ramp can be considered a component of the gravitational acceleration: a = g sinθ
Then we have an incline of angle given by Equation 1:
. (1)
The acceleration of gravity, g, acts vertically downward, so the component of parallel to the incline – which is the acceleration of our cart – is given by Equation 2:
(2)
We see in Equation 2 that a graph of acceleration a as a function of sinθ should be linear with slope g. We will take data to plot such a graph and from its slope determine the value of g.
Setup
Gather the following materials:
· 2 m ramp
· Meter stick
· Lab Stand
· Ramp clamp
· Plastic Box with ULI, AC Adapter, and USB Cable
· Motion Sensor
· Magnetic Bumper
1. Connect the ULI to the computer via the USB cable and connect the AC adapter. Open Logger Pro 3.8.7.
2. Attach the ramp clamp to the lab stand and attach one end of the ramp.
3. Elevate one end of the track slightly using the vertical rod. Choose a value of h so that the angle of inclination stays less than about 8 degrees. (Use Equation 1 to verify).
· You can choose any two points along the track to serve as your L, but they must be the same two points for all your runs!
· Measure h by measuring the difference in the two heights of your two points.
4. Connect a motion sensor to the ULI and mount it on the elevated end of the track. The low end of the track should have a magnetic bumper installed on it (magnets face upward along the track).
Procedure
1. Choose at least five values of height h, to vary over the range 1-8 degrees.
2. Record each value of h chosen, and then obtain a graph of velocity versus time for that value.
3. You have two options for collecting velocity data from the cart:
· Release from the elevated end of the track and let it accelerate to the lower end.
· Push the cart from the lower end of the track up the incline. Record data during its entire motion back to its starting point. This will take slightly more finesse, but the data will be better.
The motion sensor will not record accurate data for a cart closer than 40 cm (the limit of its near range). Do not let the cart collide with the end of the track!
4. Determine the acceleration for the cart by using the Linear Fit tool and highlighting the appropriate region of the velocity graph. Record the .
Our experiment to determine Specific latent heat of fusion of ice
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3. Instruments we need: Retort Stand Metre rule weight drop Ticker timer Ticker tape stopwatch
4. Procedure: a) Thread a length of ticker-tape through a ticker- timer and attach the end to a weight dropper b) Connect the timer to the power supply, switch on. c) Release the ticker-tape, a series of dots appears. Repeat doing so and we get several tapes. d) Stop marking the dots as soon as they start getting closer together. e) Count ten dot-to-dot spaces and cut the tape . Work out the velocity of the first and last dots as well as time.
5. f) draw a horizontal line, as a time square axis, a vertical line, as an s axis, on a piece of gridding paper.
6. g) Sketch the dots on the graph, connect them with a line. Find the gradient of the line. Errors: An error in the mechanical sense was the ticker timer clicking at exactly 1/30 of a second. If it wasn’t the results of this lab could be changed greatly. Another error could be the air resistance. Although not a big factor since this lab was preformed in a controlled environment, this factor is still present. Human error played a huge factor in this lab. Due to human error, the entire results could be false. One error could be the error of measuring. This error could effect the entire lab due to the fact that it is not exact. Another human error is the height at which the object was dropped. One of the objects could have been dropped a little higher or a little lower that the other which will make the acceleration inaccurate.