Answer:
[tex]F_{r} = 16 \ \rm N[/tex].
Explanation:
Given data:
Mass of the wooden block, [tex]m = 0.80 \ kg[/tex]
Applied force, [tex]F = 20 \ \rm N[/tex]
Acceleration, [tex]a = 5 \ m/s^{2}[/tex]
Let the magnitude of the frictional force be [tex]F_{r}.[/tex]
On applying Newton's second law of motion,
[tex]ma = F- F_{r}[/tex]
[tex]0.80 \times 5 = 20 - F_{r}[/tex]
[tex]\Rightarrow \ F_{r} = 16 \ \rm N.[/tex]
