P113. The Ballistic Cart: A Lab Problem

One type of problem that appears on every AP Physics exam is the lab problem. Some of the things that the student might be requested to do for such a problem include the following:

• Given a list of equipment, describe how to use the equipment to carry out a given experimental measurement
• Read data from a graph
• Given data, construct a graph
• Carry out a fit to data by hand; that is, draw the best fit line and determine the coefficients (slope and intercept) of the fit
• Use the coefficients of the fit to determine physical parameters of the system

In order to help prepare students for such problems, a lab problem is typically included on the comprehensive tests in the course. Such will be the case with the test on Chs. 1-4.

You already have experience in the skills required for lab problems by having completed L103 and L109. In those labs, you collected data from images provided to you. You applied an analysis to the data, prepared graphs by hand, and did a best-fit analysis. For L103, the slope of the fit represented the speed of sound. For L109, the slope of the fit was the acceleration of the glider on the air track, and the intercept of the fit was the initial velocity. Something else that you did in L109 was to determine a scale factor to convert photo distances to actual distances. This is a skill that you could be asked to demonstrate in a lab problem.

For this assignment, do problem 44 at the end of Chapter 4. Read the problem carefully to make sure you understand what is being asked for. Note that the launch speed is not the initial vertical velocity component. You'll need to take measurements from the photograph. Click here or on the image for a large version that you can print. 

We're not providing detailed, step-by-step instructions for doing this problem. This is an opportunity for you to use the physics and skills that you've learned to solve a lab-type problem. Present a clear, complete, and logically ordered solution.This will of necessity include descriptions in words describing and explaining your method. Your score will be based on the appropriateness of your method, the accuracy of your measurements, the correctness of your calculations, and the clarity and completeness of your presentation.