ANSWER:
(a) 20 m/s^2
(b) 250 m
STEP-BY-STEP EXPLANATION:
Given:
Mass (m) = 250 g = 0.25 kg
Force (F) = 20 N
Frictional force (Ff) = 15 N
(a)
The net force on the block is:
[tex]\begin{gathered} F_{net}=F-F_f \\ F_{net}=20-15 \\ F_{net}=5\text{ N} \end{gathered}[/tex]
We know that:
[tex]\begin{gathered} F=m\cdot a \\ \text{ We replacing} \\ 5=0.25\cdot a \\ a=\frac{5}{0.25} \\ a=20\text{ m/s}^2 \end{gathered}[/tex]
(b)
We can calculate the partial distance from the following equation:
initial velocity (u) = 0 (start from rest)
[tex]\begin{gathered} s=ut+\frac{1}{2}at^2 \\ \text{ we replacing} \\ s=0\cdot5+\frac{1}{2}\cdot20\cdot5^2 \\ s=250\text{ m} \end{gathered}[/tex]
