A bee with velocity vector r ′ ( t ) starts out at the origin at t = 0 and flies around for T seconds. Where is the bee located at time T if ∫ T 0 r ′ ( u ) d u = 0 ? What does the quantity ∫ T 0 ∥ r ′ ( u ) ∥ d u represent?

Respuesta :

Answer:

At time T the bee will be at (0,0).

The quantity represents the integral of function [tex][r^{'}(u)][/tex] with the time interval of (0,T).

Step-by-step explanation:

Given :

              [tex]\int\limits^T_0 {r^{'}(u) } \, du=0[/tex]

As we already know that

              [tex]\frac{dr(t)}{dt}=r^{'}(t)[/tex]

Thus we can say that

             [tex]\frac{dr(u)}{du}=r^{'}(u)[/tex]

             [tex]dr(u)=r^{'}(u)du[/tex]

Now,           [tex]\int\limits^0_T {r^{'}(u) } \, du =[r(u)]_{0}^T=r(t)-r(0)[/tex]

                   [tex]r(t)-r(0)=0\\[/tex]

                   [tex]r(t)=r(0)=(0,0)[/tex]

So at time T the bee will be at (0,0).