ANSWER
[tex]678.10N[/tex]
EXPLANATION
Parameters given:
Coefficient of static friction, μs = 0.105
Force, F = 71.2 N
The minimum force required to set the sled moving must be equal to the frictional force acting on the sled.
The frictional force is given mathematically as:
[tex]F_f=\mu_sN[/tex]
where N = normal force
Since the force required is equal to the frictional force, we have that:
[tex]F=F_f[/tex]
Therefore:
[tex]F=\mu_sN[/tex]
Solve for N:
[tex]\begin{gathered} N=\frac{F}{\mu_s} \\ N=\frac{71.2}{0.105} \\ N=678.10N \end{gathered}[/tex]
That is the normal force.
