Answer
a) See the detailed answer below.
b) See the figure below.
c) $a_x=-8\;\rm m/s^2$
Work Step by Step
a) A car is moving in a straight line toward the east at a constant deceleration. It travels 64 m in 4 seconds until it stopped when its initial velocity was 32 m/s. Find its acceleration.
b) See the figure below.
c) Solving the given formula for $a_x$;
$$a_x=\dfrac{64-(32\cdot 4)}{\frac{1}{2}4^2}=\color{red}{\bf -8}\;\rm m/s^2$$