Answer:
<em>20 m/s in the same direction of the bus.</em>
Explanation:
<u>Relative Motion
</u>
Objects movement is always related to some reference. If you are moving at a constant speed, all the objects moving with you seem to be at rest from your reference, but they are moving at the same speed as you by an external observer.
If we are riding on a bus at 10 m/s and throw a ball which we see moving at 10 m/s in our same direction, then an external observer (called Ophelia) will see the ball moving at our speed plus the relative speed with respect to us, that is, at 20 m/s in the same direction of the bus.
Answer:

Explanation:
We will apply the equations of kinematics to both stones separately.
First stone:
Let us denote the time spent after the second stone is thrown as 'T'.

Second stone:

You need to add a picture or answers!
Answer:
34883.7
Explanation:
Primero hay que convertir las dos unidades a la misma unidad-cm-
3km- 300000 cm
86mm- 8.6mm
Después hay que dividir
300000/8.6= 34883.7209302 ~ 34883.7