Introduction

In this experiment a trolley is sent down a ramp. It's velocity is measured as it passes through a lightgate after different displacements. Students have to plot a graph of v² against s including custom error bars. I have often used this experiment early in the course to help students to learn how to process data and plot graphs in this case I give them the "non assessable" worksheet which includes full instruction on what to do

 

Assessment

This practical is suitable for assessing DCP and CE only if the "assessable worksheet" is used, if the "non assessable" version is used then the DCP and CE can be addressed but not assessed.

 

DCP:

• The table should be properly constructed with headings, units and uncertainties. All values in a column should have the same significant figures. There should be at least 6 different heights and each reading should be repeated 4 or 5 times.
• The velocities must be squared correctly and the uncertainties propagated, the number of sig figs in the average velocity squared column shouldn't exceed the uncertainty.
• A graph of velocity squared against distance travelled should be plotted, this should be labelled including units. Custom error bars should be drawn and a best fit line plotted automatically. Steepest and least steep lines should also be included.

 

CE:

• The conclusion should include a value for a including uncertainties calculated from the steepest and least steep gradients, students should say if their value is reasonable. Comments should be made about the linearity of the graph.
• Weaknesses of the method should be pointed out and ways these could be addressed described.

 

Inclined plane marked report 1
Inclined plane marked report 2