Answer:
the distance is 1350 Km
Step-by-step explanation:
To solve this problem we will use the formulas of contant velocity motion:
![d=v*t\\where:\\d=distance\\v=velocity\\t=time](https://img.qammunity.org/2020/formulas/physics/college/84rkvlndl92q0dq0dnwwvcr1hbdmbtarj0.png)
Because the waves have to travel the same distance we can set the following equallity:
![vs*ts=vp*tp](https://img.qammunity.org/2020/formulas/physics/college/jdpm6h9sjyb38lp6nezdgkitudgrevq9j0.png)
We know that the s waves arrive 2 minutes later, that is 120 seconds:
![vs*(120+t1)=vp*t1](https://img.qammunity.org/2020/formulas/physics/college/f1ufharnantsm3ki2hyvzmqxna51nqvcd5.png)
Rearranging the last equation we have :
![t1=120*(vs)/(vp-vs)\\\\t1=120*(5000)/(9000-5000)\\\\t1=150seconds](https://img.qammunity.org/2020/formulas/physics/college/exusqdz9b2oqy6lliav61fhtir65ivpu3n.png)
As we said before they have to travel the same distance, so:
![d=9000((m)/(s))*150(s)\\d=1350000(m)\\d=1350(km)](https://img.qammunity.org/2020/formulas/physics/college/ajtcb3juf8zfs3w7o3znsrp5xla97kn3a5.png)