Imagine that you place a little pipette, length 1 cm on
acentrifuge with radius r=70 cm. inside the pippette, there isa
viscous liquid, with viscosity 20 times more than water. inthis
liquid there is a cell of size 1.5 micrometer. the onlyforce that
can provide centripetal acceleartion to the cell is thefriction
force which will develop if the cell moves through theliqid. find
terminal velocity fo the cell assuming centrifugerotates at 1500
rpm. assume cell density is 2 % higher thanwater.

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

the answer you are looking for is d. there are no holes for blood to enter or leave the system. your welcome