A car travels 3 km north, then turns and travels 4 km west. What is the car's
displacement?

"Displacement" is the straight-line distance and direction between the start-point and the end-point, regardless of what route was taken to get there.

If you draw a picture of how this car traveled, you'll see that it drove along two legs of a right triangle. I'm guessing the driver probably decided to stay on the streets, instead of driving the STRAIGHT line across people's lawns to get to the grocery store.  if a BIRD wanted to make the same trip, it would just fly in a straight line, straight over houses and yards.

The bird would fly along the hypotenuse of the right triangle.  The distance would be  √(3² + 4²).

That's √(9 + 16), which is √(25), and that's 5 km .

'Displacement' is a vector, and it also needs a direction.

After driving 3km north and 4km west, you are 5km roughly Northwest of where you started from.  (actually 53.1° west of north)

The car's displacement is 5 km , 53.1° west of north,

or 5 km at an azimuth of 306.9° .

c because the news are a source of information of things that happen on the daily and shows evidence about that particular topic

bacteria that live on the ocean floor are sustained by phytoplankton. phytoplankton, microscopic marine photosynthetic organisms, have a vastly significant role to play not only in the marine food web of which they’re part of, but also on a more global scale. despite their infinitely small size in comparison to other marine organisms, these tiny creatures occupy an immensely important ecological niche: they are the foundation of the marine food web, and as primary producers, play key roles in supporting all other organisms in the marine environment, as well as in the regulation of the earth’s climate through the sequestration of carbon, oxygen production, and other related processes. phytoplankton account for roughly half of all global primary productivity; therefore, their significance extends far beyond the marine environment alone. there is an intriguing sense of irony in the realization that these tiny living beings that often live out their existence unnoticed and undetected by the rest of the world, have such a far-reaching impact on the lives of virtually all other living organisms on the planet, particularly on those in the marine environment. the world that we have become accustomed to has been and is continuously shaped by the workings of these miniscule yet vital “plants of the sea”.

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