Augustana College Physics Laboratories

Hanson Hall of Science, Rock Island, IL

Mechanics Lab Skills

In addition to allowing you to deal with some of the concepts in your physics class firsthand, lab exercises are designed to help you to become a better scientist, investigator, and critical thinker. One aspect of this is learning how to properly use measuring tools, from things as simple as a ruler to computer-interfaced sensors. It also involves developing good data-taking practices, such as recording data in a complete, organized way, and providing uncertainty estimates for measurements whenever feasible. It also means learning to draw sound conclusions from results and data, using statistics, well-designed experiments, and logical thinking.

Objectives/Tasks (What You’ll Do):

  1. Determine the constant velocity of a cart launched using a consistent method
  2. Use different methods to estimate quality of measurements (uncertainty/error)

Resources (What You’ll Use):

Background:

Experimental work often involves repeated measurements, both to confirm your own results and those of others. A way to combine multiple measurements of something into a single number that expresses something about all the measurements is to simply use the arithmetic mean (\mu). The idea is that all measurements will tend to cluster around some value, and the more measurements we take, the closer the mean gets to this theoretical “actual” value (although whether the actual value exists is a subject of philosophy – we can try using more accurate instruments to get the “true” value of a measurement or take huge numbers of measurements, but there will always be uncertainty in a measurement to some degree).

In this lab, you’ll measure the velocity of a cart on a flat track. The cart is launched using a spring plunger built into one end, so that the velocity is constant and (nearly) the same each time the car is launched.

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