Lab
Video Lab: Two-Dimensional Projectile Motion
Printer Friendly Version
Introduction
In this lab you will be examining data taken from the video entitled
(Part 1 of 2) An introductory Projectile Motion Problem with an Initial Horizontal Velocity
produced by
Flipping Physics
. The following lab implementation was designed for use in my Honors Physics I and AP Physics 1 classes and only represents one method of analyzing the video. Before taking any measurements, view the video several times to acquaint yourself with its scenario and background information regarding two-dimensional projectile motion.
At this point you should have familiarized yourself with the experiment's scenario. A ball was released from a window of a car moving at a constant velocity of 10 miles/hour across a parking lot. Two cameras recorded the ball's behavior: one was attached to the car's window observing the ball's trajectory relative to the car, and a second camera was stationary recording the ball's trajectory relative to the parking lot. The goal is for the passenger to release the ball at the appropriate moment for the ball to land in a stationary bucket. Our goal during this lab is to understand how the horizontal and vertical motion of a projectile have different properties while occuring simultaneously and independently.
(1) According to the frame of reference of the camera attached to the moving car which statement correctly describes the "path" of the ball as it fell?
it stayed directly under the camera and fall straight down next to the car
it failed to keep up with the car's forward motion and followed a parabolic trajectory landing behind the car
the ball followed a diagonal, linear trajectory and arrived at the bucket simultaneously with the car
Explain your previous choice.
(2) According to the frame of reference of the camera that was stationary in the parking lot, what did the ball's trajectory look like as the it fell?
the ball had a parabolic trajectory and arrived at the bucket after the car has previously passed the bucket's location
the ball had a parabolic trajectory and arrives at the bucket simultaneously with the car
the ball fell straight down and missed the bucket
the ball followed a diagonal, linear trajectory and arrived at the bucket simultaneously with the car
Explain your previous choice.
Refer to the following information for the next three questions.
Shown below is a screen capture from the video (taken at 8:09) that has been marked up by the film maker with the actual measurements for the ball's vertical drop and its range. In this section you will determine the time the ball spent in the air and a scaling factor to convert measurements made in centimeters on the screen capture to the actual distances in meters that were occuring in the actual physical experiment.
Calculate how much time passed as the ball vertically fell the designated 0.7 meters between its point of release from the car's window and the top of the bucket.
Print the
screen capture
and measure with a centimeter ruler the distance labeled 0.7 meters. Express your answer to the nearest 1/10
^{th}
of a centimeter. Remember that larger printouts will yield better measurements!
Based on your previous measurement determine your scaling factor that will convert your measurements from your printout that were in centimeters to meters; that is, 1 cm = ______ meter.
Refer to the following information for the next seven questions.
You are now going to create a grid locating the horizontal and vertical positions of the ball's center of mass as it moves into the bucket. Your final picture will look similar to the diagram shown below. Note that the first "ball" has a vertical and a horizontal position of (0,0).
Using the "0" positions shown on the gridded diagram, measure the ball's cumulative horizontal displacement across the page. Record your results in the data table provided below first in centimeters and then converted into meters.
ball
cm measure
meter conversion
1
0
0
2
3
4
5
6
7
8
What was the difference (in meters) between your final range and the 1.7 meters shown on the screen capture?
Why was this difference expected?
Hopefully you noticed that the ball's successive horizontal positions were more or less equally spaced. Using that observation calculate a reasonable time interval, ∆t, between each position.
What would a graph of position vs time for the ball's horizontal motion look like?
linear with a negative slope
linear with a slope of zero
linear with a positive slope
Create this graph in
EXCEL
and reports its slope in m/sec.
Convert the value of your slope in the previous question to miles/hour.
What attribute of the car's motion does your previous answer represent?
Refer to the following information for the next seven questions.
Repeat this process for the vertical measurements of the ball's center of mass. Note that all of your measurements in this section should be negative since the video does all of its analysis with "down" representing a negative direction.
ball
cm measure
meter conversion
1
0
0
2
3
4
5
6
7
8
What was the difference (in meters) between your final vertical displacement and the 0.7 meters shown on the screen capture?
Why was this difference expected?
What would a graph of the ball's vertical displacement vs time look like?
linear with a negative slope
parabolic opening downward
linear with a slope of 0
parabolic opening upward
linear with a positive slope
Now return to your EXCEL workbook and plot a graph of
vertical displacement vs time squared
. This graph should be linear. What is this graph's slope in m/sec
^{2}
?
Based on the equation s
_{y}
= v
_{o}
t + ½at
^{2}
, the slope of s
_{y}
vs time
^{2}
should equal one-half of the acceleration due to gravity. What is your slope's percent error?
Refer to the following information for the next five questions.
EXTENSION. Using energy methods determine the ball's final resultant velocity as it entered the bucket. Take the zero level for potential energy to be the top of the bucket. Let the mass of the ball be 14.53 grams. In this section, give all of your energy answers in joules (J).
What givens do you need to calculate the ball's initial PE just as it was released?
What givens do your need to calculate the ball's initial kinetic energy just as it was released?
What was the ball's total energy (PE + KE) when it was released?
What type of energy did the ball have just as it entered the bucket?
If air resistance can be considered negligible, what was the ball's actual speed (resultant velocity) as it entered the bucket? If you wish to examine the
drag forces
on the lacrosse ball you should examine this
second video
.
Conclusions
The ball's horizontal behavior is classified as
uniformly accelerated
constant velocity
The ball's vertical behavior is classified as
uniformly accelerated
constant velocity
Explain how time unites the ball's horizontal and vertical behaviors.
Explain why energy methods allow you to "blend" the ball's horizontal and vertical behaviors.
According to a
later video
, the success occured on the 18th attempt. The crew filmed for roughly 1.5 hours. Now we know why the young boy was SO excited in the video!
Related Documents
Lab:
Labs -
A Photoelectric Effect Analogy
Labs -
Acceleration Down an Inclined Plane
Labs -
Ballistic Pendulum: Muzzle Velocity
Labs -
Coefficient of Friction
Labs -
Coefficient of Kinetic Friction (pulley, incline, block)
Labs -
Collision Pendulum: Muzzle Velocity
Labs -
Conservation of Momentum
Labs -
Cookie Sale Problem
Labs -
Flow Rates
Labs -
Freefall Mini-Lab: Reaction Times
Labs -
Freefall: Timing a Bouncing Ball
Labs -
Galileo Ramps
Labs -
Gravitational Field Strength
Labs -
Home to School
Labs -
InterState Map
Labs -
LAB: Ramps - Accelerated Motion
Labs -
LabPro: Newton's 2nd Law
Labs -
LabPro: Uniformly Accelerated Motion
Labs -
Mass of a Rolling Cart
Labs -
Moment of Inertia of a Bicycle Wheel
Labs -
Monkey and the Hunter Animation
Labs -
Monkey and the Hunter Screen Captures
Labs -
Projectiles Released at an Angle
Labs -
Ramps: Sliding vs Rolling
Labs -
Range of a Projectile
Labs -
Roller Coaster, Projectile Motion, and Energy
Labs -
Rube Goldberg Challenge
Labs -
Target Lab: Ball Bearing Rolling Down an Inclined Plane
Labs -
Terminal Velocity
Labs -
Video LAB: A Gravitron
Labs -
Video Lab: Ball Bouncing Across a Stage
Labs -
Video LAB: Ball Re-Bounding From a Wall
Labs -
Video Lab: Cart Push #2 and #3
Labs -
Video Lab: Falling Coffee Filters
Resource Lesson:
RL -
Accelerated Motion: A Data Analysis Approach
RL -
Accelerated Motion: Velocity-Time Graphs
RL -
Analyzing SVA Graph Combinations
RL -
Average Velocity - A Calculus Approach
RL -
Chase Problems
RL -
Chase Problems: Projectiles
RL -
Comparing Constant Velocity Graphs of Position-Time & Velocity-Time
RL -
Constant Velocity: Position-Time Graphs
RL -
Constant Velocity: Velocity-Time Graphs
RL -
Derivation of the Kinematics Equations for Uniformly Accelerated Motion
RL -
Derivatives: Instantaneous vs Average Velocities
RL -
Directions: Flash Cards
RL -
Freefall: Horizontally Released Projectiles (2D-Motion)
RL -
Freefall: Projectiles in 1-Dimension
RL -
Freefall: Projectiles Released at an Angle (2D-Motion)
RL -
Monkey and the Hunter
RL -
Summary: Graph Shapes for Constant Velocity
RL -
Summary: Graph Shapes for Uniformly Accelerated Motion
RL -
SVA: Slopes and Area Relationships
RL -
Vector Resultants: Average Velocity
Review:
REV -
Test #1: APC Review Sheet
Worksheet:
APP -
Hackensack
APP -
The Baseball Game
APP -
The Big Mac
APP -
The Cemetary
APP -
The Golf Game
APP -
The Spring Phling
CP -
2D Projectiles
CP -
Dropped From Rest
CP -
Freefall
CP -
Non-Accelerated and Accelerated Motion
CP -
Tossed Ball
CP -
Up and Down
NT -
Average Speed
NT -
Back-and-Forth
NT -
Crosswinds
NT -
Headwinds
NT -
Monkey Shooter
NT -
Pendulum
NT -
Projectile
WS -
Accelerated Motion: Analyzing Velocity-Time Graphs
WS -
Accelerated Motion: Graph Shape Patterns
WS -
Accelerated Motion: Practice with Data Analysis
WS -
Advanced Properties of Freely Falling Bodies #1
WS -
Advanced Properties of Freely Falling Bodies #2
WS -
Advanced Properties of Freely Falling Bodies #3
WS -
Average Speed and Average Velocity
WS -
Average Speed Drill
WS -
Charged Projectiles in Uniform Electric Fields
WS -
Chase Problems #1
WS -
Chase Problems #2
WS -
Chase Problems: Projectiles
WS -
Combining Kinematics and Dynamics
WS -
Constant Velocity: Converting Position and Velocity Graphs
WS -
Constant Velocity: Position-Time Graphs #1
WS -
Constant Velocity: Position-Time Graphs #2
WS -
Constant Velocity: Position-Time Graphs #3
WS -
Constant Velocity: Velocity-Time Graphs #1
WS -
Constant Velocity: Velocity-Time Graphs #2
WS -
Constant Velocity: Velocity-Time Graphs #3
WS -
Converting s-t and v-t Graphs
WS -
Energy Methods: More Practice with Projectiles
WS -
Energy Methods: Projectiles
WS -
Force vs Displacement Graphs
WS -
Freefall #1
WS -
Freefall #2
WS -
Freefall #3
WS -
Freefall #3 (Honors)
WS -
Horizontally Released Projectiles #1
WS -
Horizontally Released Projectiles #2
WS -
Kinematics Along With Work/Energy
WS -
Kinematics Equations #1
WS -
Kinematics Equations #2
WS -
Kinematics Equations #3: A Stop Light Story
WS -
Lab Discussion: Gravitational Field Strength and the Acceleration Due to Gravity
WS -
Position-Time Graph "Story" Combinations
WS -
Projectiles Released at an Angle
WS -
Rotational Kinetic Energy
WS -
SVA Relationships #1
WS -
SVA Relationships #2
WS -
SVA Relationships #3
WS -
SVA Relationships #4
WS -
SVA Relationships #5
WS -
Work and Energy Practice: An Assortment of Situations
TB -
2A: Introduction to Motion
TB -
2B: Average Speed and Average Velocity
TB -
Antiderivatives and Kinematics Functions
TB -
Honors: Average Speed/Velocity
TB -
Kinematics Derivatives
TB -
Projectile Summary
TB -
Projectile Summary
TB -
Projectiles Mixed (Vertical and Horizontal Release)
TB -
Projectiles Released at an Angle
TB -
Set 3A: Projectiles
Flipping Physics
Jon
Copyright © 2000-2018
All rights reserved.
Used with
permission
.
PhysicsLAB
Lab Implementation
Copyright © 2018
Catharine H. Colwell
All rights reserved.
Application Programmer
Mark Acton