A train travels between two stations that are 63 km apart at an average speed of 35 m / s . How long after leaving the first station did the train arrive at the second station ?

here we know that ball will drop down by total distance 3.2 m

so here we know that

now using kinematics

now in the same time it will cover horizontal distance of 0.75 m

so speed of the ball will be

the answer is 3.1 his answer is wrong mines is right

when jerome paddle in flowing river towards east the net speed of jerome will increase

so the net speed of jerome will be given as

now the speed of paul will be same as it is given as he is running on the ground

so

so here we can say since the speed of jerome is more so he will win the race

now as we know the distance so the time difference is given as

so jerome will reach first and the time difference will be 203.55 s or 3.4 min

3. dark matter

empty space could also be a simple vacuum