- - Calculator;
- - dynamometer;
- - line.
Connect the load cell body and pull it out, deform the body.The power that the load cell will be equal to the modulus of elasticity of the force acting on a body.Find stiffness coefficient using Hooke's law, which says that the elastic force is directly proportional to its elongation and is directed opposite to the strain.Calculate the ratio of the stiffness by dividing the value of the force F on the elongation of the body x, which is a ruler or tape measure k = F / x.To find the extension of the deformed body subtract the length of the deformed body of its original length.Stiffness coefficient is measured in
N / m.
dynamometer If not, hang to the deformable body load of known weight.Make sure the body is elastically deformed and collapsed.In this case, the load weight is equal to the elastic force acting on the body, the stiffness coefficient to be found, for example, springs.Calculate the ratio of the stiffness by dividing the product of the mass m and the acceleration of gravity g≈9,81 m / s² in the elongation of the body x, k = m • g / x.Elongation measure by the method proposed in the previous paragraph.
example.Under a load of 3 kg spring is 20 cm long was the 26 cm, determine its rigidity.First, find the spring extension in meters.For this purpose the length of the elongated spring, subtract its length in a normal state x = 26-20 = 6 cm = 0.06 m. Calculate stiffness using the corresponding formula k = m • g / x = 3 • 9,81 / 0,06≈500 N / m.
In that case, when we know the potential energy of the elastically deformed body, calculate its stiffness.To this end, an additional measure of its extension.Rigidity is twice the potential energy Ep divided by the square of the elongation of the body x, k = 2 • Ep / x².For example, if the ball was deformed to 2 cm, and the potential energy received J. 4, its rigidity k = 2 • 4 / 0,02² = 20000 N / m.