Lab Experiment

What Do You Think?

Using the definition of work in the background section, is work done when a person is studying? Is work done when a person lifts a backpack up from the floor?

Take time to answer the 'What Do You Think?' question(s) in the Lab Report section.

Background

For an object with mass m that experiences a net force Fnet over a distance d that is parallel to the net force, the work done is:

If the work changes the object's vertical position, the object's gravitational potential energy changes. However, if the work changes only the object's speed, the object's kinetic energy changes as follows:

where W is the work, vf is the final speed of the object and vi is the initial speed of the object.

SAFETY REMINDER

* Do not let the cart run away from the user. Catch the cart before the cart crashes into the bumper or travels off from the table.

* Follow the directions for using the equipment.

For You To Do

The purpose of this laboratory activity is to compare the work done on an object and the change in kinetic energy of the object. Use the Force Sensor to measure the force applied to the cart. Use the Photogate/Pulley System to measure the motion of the cart as it is pulled by the weight of the hanging mass. Next, use DataStudio or ScienceWorkshop to plot and analyze the data.

PART I: Computer Setup

1. Connect the ScienceWorkshop interface to the computer, turn on the interface, and turn on the computer.

2. Connect the Photogate's phone plug to Digital Channel 1.

3. Connect the DIN plug of the Force Sensor to Analog Channel A.

4. Open the document titled as shown:

DataStudio ScienceWorkshop (Mac) ScienceWorkshop (Win)

P19 Work Energy.DS P22 Work-Energy Theorem P22_WORK.SWS

* The DataStudio document has a Workbook display. Read the instructions in the Workbook.

* The ScienceWorkshop document has a Graph display of Force vs. Distance and a Table display of Speed.

* Data recording is set at 50 Hz for the Force Sensor.

PART II: Sensor Calibration and Equipment Setup

* You do not need to calibrate the Photogate/Pulley System.

* To