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A car slows down from 24 m/s to rest in a distance of 90 m. what was its acceleration, assumed constant? incorrect: your answer is incorrect. m/s2

Respuesta :

The initial speed of the car is
V₁ = 24 m/s

Because the car comes to rest, the final speed of the car is
V₂ = 0

The distance traveled while coming to rest is
d = 90 m.

Let a =  the constant acceleration.
Use the formula
V₂² = V₁² + 2ad

That is,
0 = (24 m/s)² + 2*(a m/s²)*(90 m)
Obtain
180a = -576
a = -3.4 m/s²

Because the answer is negative, the car decelerates.

Answer:
The acceleration is -3.2 m/s² (or a deceleration of 3.2 m/s²).

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