You are traveling upstream on a river at dusk. you see a buoy with the number 4 and a flashing red light. what should you do?

Upstream or upriver is a term which is used when you are travelling against the direction of the flow of the river. There are some markers or symbols which are telling us something or how we should pass.
when you are travelling at dusk and you see a buoy with number 4 and a flashing red light you should keep the buoy on the starboard side that is on the right side. buoy with number 5 or any other number will indicate something different.

The objects are acted upon by only one force. gravity. mass times the acceleration of gravity (-9.81meters/second squared).

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