2.5 Physical Applications 

[STARTS AT 2:14]

PROFESSOR: Next, consider a thin rode oriented on the x-axis over the interval 1 to 3. If the density of the rod is given by rho of x equals 2x squared plus 3, what's the mass? Well, again, based on our formula, our mass is the integral from a to b-- so from 1 to e-- of rho of x, 2x squared plus 3 dx. Now, that quantity is our integrand there. 

Well, that is going to integrate as 2/3 x cubed-- using our inverse power rule-- plus 3x evaluated from 1 to 3. And, again, the algebra is up to you-- the plugging that in. And this should be 70/3.

[ENDS AT 3:01]