Hypeovernecia70
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A drag racer starts her car from rest and accelerates at 14 meters per second per second for the entire distance of 424 meters. how long does her race take

Respuesta :

kudzordzifrancis
You can use this 'suvat' equation of linear motion

[tex] s = ut + \frac{1}{2} a {t}^{2} [/tex]
From the question, the racer starts from rest so the initial velocity
[tex]u = 0 {ms}^{ - 1} [/tex]

The acceleration,

[tex]a= 14 {ms}^{ - 2} [/tex]

And distance
[tex]s = 424m[/tex]

We can substitute this values to find t

[tex] 424= (0)t + \frac{1}{2} (14) {t}^{2} [/tex]

[tex] 424= 7{t}^{2} [/tex]

Dividing by 7, we have

[tex] \frac{424}{7} = {t}^{2} [/tex]

[tex] \sqrt{ \frac{424}{7} } = t[/tex]

[tex]t = 7.8 \: s[/tex]

Therefore the race took 7.8 seconds

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