Answer:
23.08 seconds
Step-by-step explanation:
The computation of the time required is shown below
Relative Velocity,V is
= 780 - ( - 780)
= 1560 km/h
As it is moving in inverse or an opposite direction
And, the Distance, D = 10 km
So the time is

= 0.00641 hours
=

= 23.08 seconds
By dividing the distance from the relative velocity we can get the time and the same is to be taken in the computation part