The height of the empire state building is 318 m if a stone is dropped from the top of the building what is the stones velocity just before it strikes the ground

79 m/s. A stone dropped from the top of the Empire State Building will have a velocity of 79 m/s just before it strikes the ground.

This problem is about free fall, to find the velocity of the stone before it strikes the ground we have to use the equation , the initial velocity  of the stone is 0 m/s. Then:

Solving the equation above with g = 9.8 m/s², and h = 318.0 m:

≅ 79 m/s

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