00:01
When you draw a stress -strain diagram, that is, on y -axis, if this is stress and this is strain, let's say for cast iron or something like a low -carbon steel, so it will be something like this.
00:23
So here, up to this point, one can see that the slope is constant.
00:30
So this particular slope represents the young modulus, that is, young modulus is equals to stress divided by strain, which is represented by this slope.
00:50
Or also in physical terms, it represents the mechanical property of any particular substance which is tested or tend to.
01:03
To have tensile or compressive stress force over it.
01:09
So it depicts the tensile or compressive stiffness of a solid material when force is applied at any cross -section in lengthwise direction or longitudinally.
01:24
Now coming to the second term that is hooke's law, it basically states that a force needed to extend or compress a spring by some distance.
01:34
Is linearly proportional to that distance.
01:40
For example, if this is the spring, and let's suppose this is the natural length l, if we apply force in downward direction, so the change in length becomes delta l.
01:53
So the net force applied f will be directly proportional to delta l, that is the exact change in length.
02:02
So one can write f is equals to kl, where k is a constant factor characteristics of any spring, which also further depends on various other factors...