Which of these is an example of work being done on an object a. Holding a heavy piece of wood at a construction site. b. Trying to push a car that doesn't move out of deep snow. c. Pushing a child on a swing. d. Holding a door shut on a windy day so it doesn't blow open.

I would say the best choice, would be Choice C.

the independent variable, the one that is intentionally manipulated, is whether or not the car hits the barrier.

the dependent variable, the one that you measure the response in, is the distance that the washers travel.

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