The demonstration is supposed to show that the equilibrant is equal and opposite to the resultant of 2 forces.

 

My teacher suggested to nail some nails equidistantly around a circle on a wooden board. Then hook 2 force gauges onto 2 nails and a key ring in the center of the circle. Then hook a 3rd force gauge onto another nail and the key ring.

 

Then measure angles and look at the force gauge to use a vector diagram to show that the key ring will be in equilibrium if and only if the 3rd force is equal and opposite to the sum of the first two.

 

Does it seem sound in theory?

The demonstration is supposed to show that the equilibrant is equal and opposite to the resultant of 2 forces.

 

My teacher suggested to nail some nails equidistantly around a circle on a wooden board. Then hook 2 force gauges onto 2 nails and a key ring in the center of the circle. Then hook a 3rd force gauge onto another nail and the key ring.

 

Then measure angles and look at the force gauge to use a vector diagram to show that the key ring will be in equilibrium if and only if the 3rd force is equal and opposite to the sum of the first two.

 

Does it seem sound in theory?

 

Yes. It's a common physics lab concept.