To determine the acceleration of a car, we need to use the concept of acceleration from physics. The formula for acceleration ([tex]\(a\)[/tex]) is given by:
[tex]\[ a = \frac{\Delta v}{\Delta t} \][/tex]
where:
- [tex]\(\Delta v\)[/tex] is the change in velocity.
- [tex]\(\Delta t\)[/tex] is the time interval over which the change in velocity occurs.
Micah knows the change in velocity of the car, which is [tex]\(\Delta v = 15 \, \text{m/s}\)[/tex]. To calculate acceleration, Micah still needs to know the time interval, [tex]\(\Delta t\)[/tex], during which this change in velocity occurred.
Among the provided options:
- distance: not necessary for calculating acceleration directly from the given change in velocity.
- time: crucial for determining acceleration.
- Ma: not relevant in this context.
- direction: not needed for the calculation of acceleration from the change in velocity.
- speed: while related, it is not directly needed to calculate acceleration in this specific case; we need the time interval.
Therefore, the essential piece of information Micah requires to determine the acceleration is the time interval (option "time").
Thus, the correct answer is time.
