Chapter 2 - One-Dimensional Kinematics - Problems and Conceptual Exercises - Page 51: 56

(a) $17~m/s^2$ (b) $51~m/s$

$v_0=0$, $x_0=0$, $x=77~m$ and $t=3.0~s$ (a) $x=x_0+v_0t+\frac{1}{2}at^2$ $77~m=0+0(3.0~s)+\frac{1}{2}a(3.0~s)^2$ $77~m=a(4.5~s^2)$ $a=\frac{77~m}{4.5~s^2}=17~m/s^2$ (b) $v=v_0+at$ $v=0+(17~m/s^2)(3.0~s)=51~m/s$