Forţa de rezistenţă la înaintare pe care o întâmpină o maşină reprezintă o fracţiune f=0,15 din greutatea ei. Ce putere are motorul dacă masa autoturismului este 1,5t şi atinge viteza maximă de 144km/h?

777.59N

Explanation:

(The forward strength of a car is a fraction f = 0.15 of its weight. What power does the engine have if the mass of the car is 1.5t and reaches a top speed of 144km / h?)

F = Mass * acceleration

Acceleration =change in velocity / time

F = Mv / t

F = 0.15mg

M = 1.5t

g = 9.8 m/s

V = 144 km/hr= (144 * 3600) / 1000 = 518.4 m/s

0.15mg = mv / t

0.15 * g = v/t

0.15 * 9.8 = 518.4 / t

1.47t = 518.4

t = 518.4 / 1.47 = 352.65s

But mass = 1.5t

Mass = 1.5 * 352.65 = 528.97kg

F = mv / t

F = (528.97 * 518.4) / 352.65

F = 777.59N

the total distance traveled by the car is

30km + 49km = 79 km .

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