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Assume you are driving in a car with a total mass of m = 1250 kg at vi = 20 m/s. You see a light turn red half a mile in front of you and take your foot o the gas. If the wind resistance and all frictional forces combine to supply a force of Fnet = 1000 N, what is your speed after 5 s? What is your speed after 30 s?

Respuesta :

Answer:

After 5 sec speed of the car will be 24 m/sec and after 30 sec speed of the car will be 44 m/sec

Explanation:

Mass of the car m = 1250 kg

Initial velocity of the car [tex]v_i=20m/sec[/tex]

Net force is given [tex]F_{net}=1000N[/tex]

From newton's law F = ma, here m is mass and a is acceleration

So [tex]1000=1250\times a[/tex]

[tex]a=0.8m/sec^2[/tex]

From first equation of motion

[tex]v_f=v_i+at[/tex]

For t = 5 sec

[tex]v_f=20+0.8\times 5=24m/sec[/tex]

For t = 30 sec

[tex]v_f=20+0.8\times 30=44m/sec[/tex]