Under a concept of calculation of a spring the large number of parameters, such as diameter of a bar, its properties on material and its processing disappears. Therefore full calculation of a spring – very difficult operation which is carried out by means of special computer programs. Refer rigidity of a spring, the maximum force of compression (stretching), the maximum deformation, spring height in the compressed and free state to the main characteristics and a spring step.

## It is required to you

- dynamometer, ruler, scales.

## Instruction

1. Take any spring and measure its length by means of a ruler. It will be spring height in a free state. Then as much as possible squeeze it, having worked with some force. Again measure spring length. It will be spring height in the compressed state. You take all measurements in meters.

2. Count quantity of rounds of a spring, then divide into this number spring height in a free state. The spring step in a free state will be result. Do the same operation for a spring in the compressed state and receive a spring step in the compressed state.

3. To find the maximum deformation of the compressed spring, take away from its height in a free state, height in the compressed state. It will be deformation on compression. To find the maximum deformation on stretching, fix one of the ends of a spring, begin to stretch it for other end, using at the same time a dynamometer. Indications of a dynamometer have to increase in proportion to lengthening of a spring as soon as indications of a dynamometer began to accrue quicker, than there is a deformation, stretching needs to be stopped. Measure length of a spring and take away from it spring length in a free state, receive the maximum deformation on stretching. Indications of a dynamometer at this moment will answer the maximum force of stretching.

4. To find the maximum force of compression, load a spring until when it completely contracts. On scales measure the mass of cargo and increase it by the acceleration of gravity (number 9.81). Express weight in kilograms, then receive force in newtons.

5. To find rigidity of a spring, fix one of its ends, and attach a dynamometer to another, give to a spring small deformation (10-20%). Measure its length in the deformed state in meters, and take readings of a dynamometer in newtons. Take away length of the deformed spring from spring length in a free state. Then divide force measured by k=F/Δx dynamometer into the received value. Receive result in newtons on meter.