PowerPoint for use with this demonstration (right-click, save link as): Tension.ppt.
The answers all are 10 N except for the free fall example where the tension is 0 N.
NCEA & Science Curriculum
SCI 1.1, PHYS 2.4
With the use of the video camera, computer running VideoPoint Capture or similar software, and a data projector, this demo is suitable for a large auditorium. The scale can be read from the back of a lecture theatre. The small mass attached to the scale helps keep the scale vertical for better viewing.
See PowerPoint below for one version of the demonstration that starts with a 1 kg mass suspended by a string, moves to a mass suspended over a pulley (left above) and then to two masses suspended by a pulley. One can then continue with a mass and force meter dropped, and a string at an angle. Ask students to predict answers using the ABC cards or a personal response system (clickers).
Watch your feet! The 1 kg masses are pretty high up.
Individual teachers are responsible for safety in their own classes. Even familiar demonstrations should be practised and safety-checked by individual teachers before they are used in a classroom.
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This teaching resource was developed with support from