Question

a car traveling on a straight road at 15 m/s accelarates uniformly to a speed of 21 meters per second in 12 seconds. the total distance traveled by the car in this 12 second time intervel is.....

i know the answer is 216 m
BUT HOW?

Answer 1

Steps to solving physics problems:
1. Diagram
2. Variable list
3. Equation.

Answer 2

Here,
v1= 15m/s
v2= 21 m/s
t=12
d=?

Answer 3

Now, here it looks like the you could use one of the big 5 kinematic equations.