Final answer:
To find the final velocity of a car that accelerates from rest at 4 m/s² for three seconds, use the equation v = u + at. With an initial velocity of 0 and substituting in the given values, the final velocity is 12 m/s.
Step-by-step explanation:
To calculate the final velocity of a car that accelerates from rest, we can use the kinematic equation that relates velocity, acceleration, and time:
v = u + at
where:
- v is the final velocity
- u is the initial velocity (from rest, so u = 0)
- a is the acceleration
- t is the time
In this problem, the car accelerates from rest (u = 0) at an acceleration (a) of 4 m/s² for a time (t) of 3 seconds.
Substituting the known values into the equation, we get:
v = 0 + (4 m/s²)(3 s)
v = 12 m/s
Therefore, the final velocity of the car after accelerating for three seconds is 12 m/s.