a c accelerates from rest in a straight line. after 12 seconds, it's velocity is measured as 42 m/s. use one of the linear equations of motion to calculate the car's acceleration

a = 42m/s / 12s = 3.5 m/s^2

or, use v=at, so a=v/t

To calculate the car's acceleration, we can use one of the linear equations of motion. In this case, since the car starts from rest and we are given the time and final velocity, we can use the equation:

v = u + at

Where:
v = final velocity (42 m/s)
u = initial velocity (0 m/s, as the car starts from rest)
a = acceleration (unknown)
t = time (12 seconds)

Now, rearrange the equation to solve for acceleration (a):

a = (v - u) / t

Plug in the given values:

a = (42 m/s - 0 m/s) / 12 s

Simplify the equation:

a = 42 m/s / 12 s

Now, divide the numerator by the denominator:

a = 3.5 m/s^2

Therefore, the car's acceleration is 3.5 m/s^2.