Dropping golf balls on the job

While "dropping the ball" usually connotes a failed effort, a missed opportunity, or a lost chance to win, in physical science golf ball dropping can produce remarkably accurate estimates of the acceleration of gravity.



The golf balls are dropped from heights ranging from 50 cm to 300 cm. The drop time for each height is measured five times, and then the average of the five drops is calculated.



Done right, the science laboratory is all about working effectively as a team and discussing results. Learning happens.



The one dropping has to time to eliminate reaction time errors. The data is first graphed as time versus distance, producing a parabola. As the students only know how to run a linear regression using the LINEST function in OpenOffice.org Calc, the students square the time and then make a separate plot of the time squared against the distance dropped. With careful measurements, this produces a straight line the slope of which is one-half g.

The laboratory guide also includes calculated the percent error based on the textbook value for g. Although the course is guided in part by constructivism, the course does not pretend that no one else has ever done science on the planet.




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