A boat moves through the water of a river at 8 m/s relative to the water, regardless of the boat's direction. If the water in theriver is flowing at 1.9 m/s, how long does it take the boat to makea round trip consisting of a 260 m displacement downstream followedby a 260 m

68.88 m/s

Explanation:

downstream speed = 8+1.9=9.9 m/s

upstream speed = 8-1.9= 6.1 m/s

Therefore, total time taken would be 260/9.9+260/6.1 = 26.26+42.62 =

68.88 m/s

as we know our atmosphere or air have different levels. every level has other gasses, and every gas has another permeability. when the light comes from lower permeability to higher permeability, it changes its direction. so that means that when the light comes from the moon to the earth, it changes it's direction many more times. it basically means that the shape of the light part of the moon is changed on the earth.

hope this ! this is not copied! search it up, it's free of plagiarism!