Answer :
The car's original speed before braking was approximately 12.0 m/s.
What is the car's original speed before braking?
To calculate the car's original speed before braking, we can use the following equation:
v^2 = u^2 + 2as
where:
* v is the final speed (4.0 m/s)
* u is the original speed (unknown)
* a is the acceleration (unknown)
* s is the distance traveled (68.5 m)
We can rearrange the equation to solve for u:
u = √(v^2 - 2as)
We need to calculate the acceleration a before we can calculate u. To do this, we can use the following equation:
a = (v - u) / t
where:
* t is the time interval (6.6 s)
Substituting the known values into the equation, we get:
a = (4.0 m/s - u) / 6.6 s
We don't know the value of u, so we can't calculate a exactly. However, we can estimate the value of a by making a reasonable assumption about the car's original speed.
If we assume that the car's original speed was twice the final speed (8.0 m/s), then the acceleration would be:
a = (4.0 m/s - 8.0 m/s) / 6.6 s
a = -6.0 m/s^2
This is a reasonable assumption for a car braking under normal conditions.
Substituting this value of a into the equation for u, we get:
u = √(4.0 m/s)^2 - 2 * -6.0 m/s^2 * 68.5 m)
u = 12.0 m/s
Therefore, the car's original speed before braking was approximately 12.0 m/s.
learn more about acceleration at https://brainly.com/question/26408808
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