Answer:
When there is wind it takes longer
Explanation:
With no wind, the round trip time is
[tex]t_1=\frac{d}{v}+\frac{d}{v}=\frac{2d}{v}[/tex]
When we have a constant wind speed w
[tex]t_2=\frac{d}{v-w} +\frac{d}{v+w} =\frac{2vd}{v^{2} -w^{2}}[/tex]
comparing the reciprocal times;
[tex]\frac{1}{t_2}=\frac{v^{2}-w^{2} }{2vd}=\frac{v}{2d}-\frac{w^{2}}{2vd} \leq \frac{v}{2d}=\frac{1}{t_1}[/tex]
This means that t1 is smaller than t2, ergo, it takes longer with wind
