How do you make a model of spring balance?

Answer 1

Take 4 or 5 rubber bands and tie them together to make a string 15-20cm long. Fashion a pan out of an index card and a paper clip and attach it to the end of the rubber band string, it should look like an inverted parachute. Attach the other end of the rubber band string to a fixed point like the top rail of a chalkboard or another surface that can be marked. Place a mark on the chalkboard at the very bottom of the pan. Place a known weight in the pan and make another mark at the lower level. Divide the weight by the distance moved and note this number, it is known as the "spring rate".

Say that the pan moved down 25mm when a weight of 100gm was weighed, then place marks every 25mm down the chalkboard and mark them as intervals of 100gm. Subdivide the marks for more accuracy, in this case, 2.5mm per 10gm. You now have a fairly accurate scale.

Answer 2

To make a model of a spring balance, you can use a spring, a hook to attach objects to be weighed, and a calibrated scale to read the weight. Secure one end of the spring to a fixed point and attach the hook to the other end to hang objects. When an object is hung on the hook, the spring will stretch, and the scale will indicate the weight based on the amount of stretch.