#### Answer

x=8.5 m, t=2.7 s, and m = 0.66 kg.
a). $v= \frac{x}{t}=\frac{8.5 m}{2.7 s}=3.1 m/s. $ (rounded off)
$p=mv=0.66 kg \times 3.1 m/s = 2.0 kg.m/s$ (rounded off)
b). $p=\frac{mx}{t}=\frac{0.66 kg \times 8.5 m}{2.7 s}=2.1 kg.m/s$ (rounded off)
c). The answers are not same because of rounding off in an intermediate step in a).