A force of 91.02 N is used to push a 6.44 kg box across the floor a distance of 1.16 m. The coefficient of friction between the floor and the box is 0.581. What is the net
work done?

one person pulls 90n one way and the other has 100n pulling the other way.

so the net force = 90 - 100 = -10n,

or the ans can be 10n if the picture shows -90n and 100n instead.

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

find the sum of the two horizontal vectors and the sum of the two vertical vectors

isoceles right angled triangle