Respuesta :
Answer:
the speed at which Noelle walks from point B to A, v=7.5 kilometers per hour
Explanation:
In this question we have given
average speed for the entire trip,S = 6 kilometers per hour
Speed of Noelle while walks from point A to B= 5 kilometers per hour
Therefore, time taken by Noelle to walks from point A to B,[tex]t_{1}=\frac{d}{5}[/tex]
Let us consider distance between A and B is d.
Therefore total distance covered in moving from point A to B and then moving back from point B to A, =[tex]d+d=2d[/tex]
Let v be the speed at which Noelle walks from point B to A
Therefore time taken by Noelle to walks from point B to A,[tex]t_{2}=\frac{d}{v}[/tex]
we know that average speed S is given as
[tex]S=\frac{x}{t}[/tex]................(1)
here, x (=2d) is total distance
and t (=[tex]t_{1}+t_{2}[/tex] ) is total time
put values of S, x and t in equation 1
[tex]6 =\frac{2d}{\frac{d}{5}+\frac{d}{v} }[/tex]
on solving we get,
v = 7.5 kilometers per hour
Therefore, the speed at which Noelle walks from point B to A, v=7.5 kilometers per hour
