00:01
Hi, in this question we will be dealing with a solid that is bounded by a square z is equal to 0, x varies from 0 to 2, y is varying from 0 to 5 and above the surface z is equal to x plus y plus 5 and density is given to be equals to 1 gram per centimeter cube.
00:25
With x, y, z all are measured in centimeter we need to find the mass of the solid where as we know we can find the mass that will be equals to integration from 0 to 5 for y, integration from 0 to 2 for x, integration from 0 to x plus y plus 5 for z, dz, dx, dy.
00:48
Now solving this further as we have rho over here, substituting the value of rho and this will be equals to integration from 0 to 5, integration from 0 to 2, here we have rho as 1 and integrating with respect to z we get z limits from 0 to x plus y plus 5 dx, dy and this will be further equals to integration from 0 to 5, integration from 0 to 2, here we get x plus y plus 5 times dx, dy and this will be equals to integration from 0 to 5, here we get x square by 2 plus yx plus 5x limits from 0 to 2 then we will integrate with respect to y and this will be equals to integration from 0 to 5, here we get 2 plus 10 plus 2y dy and further solving by integrating with respect to y we get this to be equals to 60 plus 25 and further solving we get the final result for the mass of the solid as m to be equals to 85 gram.
02:04
Next we will solve for the value of x coordinate of the solid and this will be equals to 1 by m integration from 0 to 5, integration from 0 to 2, integration from 0 to x plus y plus 5, here we have x times dz dx dy and solving this further we get this to be equals to 1 by 85 integration from 0 to 5, integration from 0 to 2, here integrating with respect to z we get x times x plus y plus 5 as we have density as 1 only and dx dy and this will be equals to 1 by 85 times integration from 0 to 5 and here integrating this we get x raise to power 3 by 3 plus y times x square by 2 plus 5 times x square by 2 limits from 0 to 2 then integrating with respect to y.
03:03
Now substituting the limits and integrating with respect to y we get the final result for x coordinate and this will be equals to 53 by 51...