# Help me cross the river

if jon rows a boat at 4m/s the river is moving at 6m/s and the river is 300m how long does it take to row across. I need the equation

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cubs1908 said:
if jon rows a boat at 4m/s the river is moving at 6m/s and the river is 300m how long does it take to row across. I need the equation
think about the reference frames. if you're standing aside, how fast is the river moving? how fast is the boat moving? which is moving faster, slower?

think about it from jon's point of view. if he does no work, how fast is he moving? how fast are you moving if he is observing you? he is doing work, so how is he moving in comparison to you and the river?

hopefully that helps

Rather then trying to find the equation, i suggest you try to understand whats happening in the problem. First of all, what is jons goal? What factors influence how this happens?

this question can change drastically with the direction of the rower and river. Are they in the same direction? Are the forces perpendicular?

t=d/v

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thanks alot