# Question involving velocities and distance

drummerdimitr

## Homework Statement

Two soccer players, Mary and Jane, begin running from nearly the same point. Mary runs in an easterly direction at 4 m/s, while Jane takes off in a direction 60 degrees north of east at 5.4 m/s. (a) How long before they are 25 m apart? (b) What is the velocity of Jane relative to Mary? (c) How far apart are they after 4 s?

## Homework Equations

D=v/t
Yf=Yi+(Vy)iT+1/2at^2
Xf=Xi+(Vx)iT

## The Attempt at a Solution

T must be the same value in both equations, but I do not know how to convert velocity vectors with a 60 degree separation into distance to solve the problem. I have a test tomorrow and your input would be much appreciated!

Homework Helper
Welcome to PF!

Hi drummerdimitr! Welcome to PF! (try using the X2 tag just above the Reply box )

Hint: If you can answer (b) first, then (a) should be easy. drummerdimitr
Thanks for the quick reply, I found the answer to part c by multiplying the velocities by 4 and finding the length of the third side. I tried doing vector addition and ended up with a relative velocity of 8.17 m/s at 34.9 degrees north degrees, but unfortunately, it is not the right answer. What am i doing wrong here?

ahh … for relative velocities, try vector subtraction! 