00:01
In this question we have to find the tangent modulus at 10 .3 megapascal or 1500 psi and second modulus at 1000 psi.
00:20
Now let's first come to the question number b, that is second modulus at 6 .9 megapaascal.
00:30
So if you're going to locate, then we will find that somewhere at this point in, point, the 6 .9 megapascal will be there.
00:45
So second modulus basically says that a point on the curve is basically joined by a straight line from the origin.
00:56
Now the slope of this line, theta, let's say, basically represents the second modulus.
01:06
So, from here we can see that slope can be calculated, let's say for part b of the question, let's say tan theta 2, this is theta 2.
01:24
So tan theta 2 can be written as this length, let's say y2 and this length, let's say let's say x2.
01:42
So we can write tan theta 2 or m2 that is the slope equals to tan theta 2 equals to y2.
01:52
Now y2 can be taken as 6 .9 megapascal and x2 that is the strain.
02:01
From here we can see that the strain is around 0 .02, sorry 0 .002.
02:10
So, this is the strain.
02:15
Now when we calculate this we will find m2 equals 2.
02:22
So we will get 3 450 megapascal.
02:30
So this will be the slope on stress strain curve.
02:41
One can also write here that m2 equals to 3450 megapascal divided by meter per meter.
02:50
This is a actually unit of the strain but since meter meter will cancel out, so one can simply write this also...