A un automóvil de 15680 que se mueve a una velocidad de 20 m / s se le aplica una fuerza de 6,4 · 10 2N hasta que se Detiene. A. ¿Cuál es la masa del auto? B. ¿Cuál era su cantidad de movimiento ( momento) inicial?Ç c. ¿Cuál fue el cambio en momento del auto? D. ¿Cuánto tiempo se aplicó la fuerza? Sol:a)1,6·103Kg b)3,2·104 kgm/s C)3,2·104 kgm/s D)50s

A)  m = 1600 kg ,  B)  p = 3.2 10⁴ kg m / s , C)  Δp = - 3.2 10⁴ kg m / s

D)  t = 51.6 s

Explanation:

A) They indicate the weight of the vehicle W = 15680 N

weight is the attraction of the earth on a body

          W = m g

           m = W / g

           m = 15680 / 9.8

           m = 1600 kg

B) The momentum is defined by

           p = m v

           p = 1600 20

           p = 3.2 10⁴ kg m / s

C) the moment change is

           Δp = p_{f} -p₀

as the vehicle stops the final speed is zero and therefore the moment is zero

           ΔP = 0 - p₀

            Δp = - 3.2 10⁴ kg m / s

D) Let's use Newton's second law

            F = m a

            a = F / m

            a = 6.2 102/1600

            a = 0.3875 m / s²

Now we can use kinematics, note that as the vehicle stops, the relationship must be opposite to the speed

            v = v₀ - a t

            v = 0

             0 = v₀ - a t

             t = v₀ / a

             t = 20 / 0.3875

             t = 51.6 s

the answer is a. hope this .

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”.

hope this !