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A racecar beginning at rest accelerates at a rate of 4.0 m/s2. It takes the car 21s to reach the end of the track. How long is the track in kilometers?

Respuesta :

Answer:

2.289 km

Explanation:

We can simply solve this by applying motion equations

where  

s - distance

u - initial velocity

a-acceleration

t - time

[tex]s = ut +\frac{1}{2} at^{2}\\  = 4*21 + \frac{1}{2}*10*21^{2}  \\= 2.289 km[/tex]