point mass freefall position time function

#Point mass freefall position time function how to#

In the film, Alom and Christina use an L-shaped bracket clipped to a metre rule to press the release switch, to aid a clean release. The switch release can limit accuracy, but overall the g-ball is a quick way to collect a large number of data points.

Like most stopclocks, it measures to a resolution of 0.01 seconds. The g-ball starts timing when released and stops timing as soon as it hits the floor. There appear to be at least two manufacturers, Unilab and Mollic). We’ve found other UK suppliers: Philip Harris, Better Equipped, Breckland Scientific. These cost about £20 + VAT from education suppliers, one of which is Timstar (as of Timstar appear to have stopped selling the G Ball. Uncertainty: the interval within which the true value can be expected to lie. This is us showing our age! A better term might be ‘resolution’.Īccuracy: a result is accurate if it is close to the true value. In the film, at about 2:22, the word ‘precision’ is used to mean the timer’s smallest scale division. The ASE book The Language of Measurement (£13.50/£8.50 members) refers to precision as:Ī measurement is precise if values cluster closely. There’s more error handling in some of the other films in the series, and we’re planning to complete a film specifically about error as the series continues.

#Point mass freefall position time function how to#

Since we anticipate this practical being used early in the A level course, we’ve not included comments about how to do a full error analysis. It’s good to compare at least two methods (even if one is shown as a demonstration only), to prompt and inform discussion about precision, accuracy and uncertainty. Which of these methods you use might depend on your students’ skill, your own preference, apparatus availability, ease of data collection or processing, and class size. Use an electromagnetic switch to release a ball bearing, with triggered timing.Drop a ‘g-ball’, which times its own fall.Drop a ball and time its fall with a stopwatch.The film shows four different methods of measuring g using a falling object: