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A car is moving at a constant velocity when it is involved in a collision. The car comes to rest after 0.450 s with an average acceleration of 60.0 m/s2 in the direction opposite that of the car's velocity. What was the speed, in km/h, of the car before the collision?

Respuesta :

skyluke89

Answer:

97.2 km/h

Explanation:

We can solve the problem by using the following SUVAT equation:

[tex]a=\frac{v-u}{t}[/tex]

where

v = 0 is the final velocity of the car

u is the initial velocity

a = -60.0 m/s^2 is the acceleration (negative, as it is in the opposite direction as the velocity)

t = 0.450 s is the time it takes for the car to comes to a stop

Solving for u, we find

[tex]u=v-at=0-(-60.0)(0.450)=27 m/s[/tex]

In order to convert it into km/h, let's keep in mind that:

1 km = 1000 m

1 h = 3600 s

So we find:

[tex]u=27 \frac{m}{s} \cdot \frac{3600 s/h}{1000 m/km}=97.2 km/h[/tex]

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