Energy and Work | Protocol
INTRODUCTION. This experiment was designed to investigate the relationship between work, potential energy, and kinetic energy. Applying. Determine the relationship of work done to the change in energy. The work W done on an object is equal to the net force Fn multiplied by displacement d. Source: Ketron Mitchell-Wynne, PhD, Asantha Cooray, PhD, Department of Physics &.
Student Sample Reflection Since work and energy are fresh in the students' minds after the video introduction, students are ready to spring into today's limited-instruction lab. This is a 2 part lab, so I allow students to choose their own lab groups of people. My students are mature and have a good rapport with each other, so I never have to worry about someone being left out of a grouping.
I announce to students that they should get started, as long as they have a cart, several masses, a piece of string, and a meter stick. They are already familiar with the expectation that they need to check their lab stations to ensure they have the right materials.
It is my rule that if something is missing at the end of the class, that group is charged with the cost of the missing item. I find doing this holds kids accountable and ensures my materials don't fall into someone's pocket. In today's lab, students are investigating the relationship between the work done on an object, its mass, and the distance it is raised.
They start by designing a ramp and measuring the mass of the cart without any additional masses. This lab will demonstrate this conservation.
Energy can be defined as "the ability to do work," which relates mechanical energy with work. Flying projectiles that hit stationary objects do work on those stationary objects, such as a cannonball hitting a brick wall and breaking it apart or a hammer driving a nail in to a piece of wood. In all cases, there is a force exerted on a body, which subsequently undergoes displacement.
An object in motion has the ability to do work, and thus it has energy. In this case, it is kinetic energy. In this experiment, gravity will be doing work on gliders. The transfer of the potential energy of gravity to translational kinetic energy will be demonstrated in this experiment by sliding a glider down air tracks at various angles i. The potential energy of an object is directly proportional to its height. The net work done on an object is equal to the change in its kinetic energy; here, the glider will start from rest and then gain kinetic energy.
This change in kinetic energy will be equal to the work done by gravity and will vary depending upon the starting height of the glider. The work-energy principle will be verified by measuring the starting height and the final velocity of the glider. Principles Potential energy is associated with forces and is stored within an object.
It depends upon the position of the object relative to its surroundings. An object raised off the ground has gravitational potential energy because of its position relative to the surface of the earth. This energy represents the ability to do work because, if the object is released, it will fall under the force of gravity and do work upon what ever it lands on.
For instance,dropping a rock on a nai lwill do work on the nail by driving it into the ground. Suppose an object is moving in a straight line at velocity v0. To increase the velocity of the object up to v1, a constant force Fnet would need to be applied to the object. Equation 1 In the case of the moving object, if the force is applied in the direction parallel to the motion of the object, then the net work is simply equal to the net force times the distance traveled: Equation 2 From kinematics, it is known that the final velocity of an object under constant acceleration is: Now consider gravitational potential energy.
This is the amount of work the object can do after falling a vertical distance h and is defined as the gravitational potential energy, PE: The higher the object is placed above the ground, the more gravitational potential energy it has. From the work-energy principle, it is known that this gravitational potential energy should then be equal to the change in kinetic energy: Equation 8 Procedure Obtain an air supply, bumpers, two gliders of varying mass, a velocity sensor, an air track, an aluminum block, and a scale see Figure 1.
Place the lower-mass glider on the scale and record its mass. Connect the air supply to the glider track and turn it on.
Work, Energy, and Power
Place the aluminum block under the glider stand,close to the air supply. This will be the lowest-height configuration. Place the glider at the top of the track and measure the height, h1. The measurement should be with respect toits approximate center of mass. Place the glider at thebottom of the track and measure the lower height, h0. The differenceh1 - h0 should be the height of the aluminum block, but perform the measurements to verify. Place the glider back on the top of the track, just above the leg and aluminum block, and release it from rest.
Record its velocity v at the bottom of the track using the timing gates. Ensure that the velocity is measured with respect to the point where h0 was measured. The tables should have a row and column format; column headings should be clearly stated; units should be provided; work should be clearly shown for all calculated data.
Spring Energy Lab Question: What is the total amount of mechanical energy for a mass on a spring at four different locations along its trajectory? To compare the total amount of mechanical energy of a mass on a spring at four different positions along its trajectory and to compare the results to the expected results.
The data section should provide a graphic labeling the four locations in the trajectory of the mass which were analyzed. It should include two tables of data - one for collected data and one for calculated data. Averaging and percent differences can be used. Elastic Cord Spreadsheet Study Question: To be identified by the student.
In this lab, you will be provided a spreadsheet which models the motion of a vertically moving object attached to a spring or a spring-like system. The object is under the influence of spring, gravity and air resistance forces. Input variables for the spreadsheet include object spring constant, spring location, object mass, initial height, initial velocity, launch angle, acceleration of gravity, and cross-sectional area.
Output variables include velocity, air resistance, net force, acceleration, position and energy values - each being listed as a function of time. You will identify a purpose you wish to study using the spreadsheet.
You must run at least two trials as a comparison-contrast associated with your question.
The Purpose should be a succinct statement which focuses on an intriguing and ambitious question which can be answered by the spreadsheet.
The Description of Study section should include a discussion of how you conducted your study so as to accomplish the purpose; explain what input variables you modified or kept fixed and what output variables you observed.
Lab Experiment: Work, Potential Energy, and Kinetic Energy
The Data section should list the input data and include pertinent output data related to your purpose. Stopping Distance Lab Question: What is the mathematical relationship between the stopping distance of a car and the initial speed of the car before braking?
To determine the mathematical relationship i. The Data section should organize the collected data in a table with labeled column headings and units. A plot of stopping distance versus speed should be included; linear or power regression should be performed and the results equation, statistical information, etc.
Energy and Work
The Conclusion should answer the question posed in the Purpose. The Discussion of Results section should use theoretical considerations to discuss the expected relationship; the degree to which the experimental results match the theoretically predicted results should be discussed.
How does the work done upon a cart compare to the potential energy change of the cart as it is pulled up a hill at a constant speed by a horizontal force? To compare the work done on a cart to the potential energy change of the cart asit is pulled up a hill at a constant speed by a horizontal force. The Data section should include a table of collected and calculated data or two tables.