00:01
Hello students in this question we are given that we have a strip of a 36 steel so this is the type of steel we have a strip of this steel and it is said that the allowable bending stress so we're gonna write out what is the various things that are provided was the given to the so the allowable bending stress that is the amount of stress that we can provide to this strip of steel and the amount of stress that it this strip can maintain itself without breaking which is the allowable bending stress that we give us sigma b allowable is equal to 165 megapass that is equal to 165 newton per millimeter square now we are provided with the modulus of elasticity for the 836 steel type so we have the the modulus of elasticity that is e is equal to 200 jesus pascal that is equal to 200 multiplied by 10 to the power 3 newton per millimeter square we are also provided with the dimension of the of the of the steel strip that we have the width of the strip is equal to 10 millimeters and the thickness of the strip is given to be equal to 1 .5 millimeters.
01:38
So in part a of the question we are asked that if the strip is folded into a circular cover, what will be the radius of the cover? that means that if we have a strip of steel and then we fold it in this way to form a circular cover, what is going to be the radius of this cover? so we need to find out what is the radius of this till, what is the minimum radius of the minimum radius to which this steel strip can be rolled up.
02:08
So if we have a straight steel strip and then we roll it over into a circular cover, what is the minimum radius to which it, this strip can be rolled up without it breaking.
02:20
So we know that as per the bending equation.
02:23
So we know as per the bending equation, as per the bending equation, we have gamma b by y, is equal to e divide so r here r would be equal to simply e multiplied by y divided by y divided by gamma b allowable since we are finding out what is the minimum radius to which this this singular steel strip can be rolled up to and here y is the thickness so this is why is here equal to t by two that is thickness divided by 2 gamma be allowable so putting the values of all the parameters here we get thus e is equal to 200 multiplied by 10 to the power 3 multiplied by 2 .1 .5 whole divided by 2 multiplied by 165 so this we will get in nanometers this will get in millimeters so on making this calculation we get the value of r to be equal to 909 .0909 .0909 0901 millimeter or we can say that radius of the of the rolled up steel strip is nearly equal to 909 .1 millimeter.
04:17
So this is the minimum radius of the of the rolled up seal strip without it actually breaking.
04:26
Now in the second part of the question we are asked to find out the corresponding maximum internal moment developed in the strip.
04:34
So we need to find out what is the corresponding maximum moment developed in the strip.
04:40
We can just write here the maximum moment...