In this Activity, you will analyze three different cases of a thin film between two materials. Consider what happens when light starts in the top material (e. g. air for Case 1), will light reflecting off of surface A undergo a phase shift, will light reflecting off of surface B undergo a phase shift? Then consider what happens when light starts in the bottom material (e. g. glass for Case 1).

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