Question

An object moving at an acceleration of 0 m/s^2 has a mass of 3 kg and friction being u= 0.1 between it and it’s surface. What is the applied force (f) to the object?

Answer 1

So given that the object has no acceleration

So net force on the object must be zero (from Newton's second law, F=ma)

Force of friction on the object is,

$F_{friction}=\mu N$

where mu is the coefficient of friction and N is the normal force,

Here the normal force is just the weight of the object,

$N=mg$

so,

$F_{friction}=\mu mg$

And so this has to be balanced by the applied force in the opposite direction to friction force,

$\begin{gathered} F_{applied}=F_{friction} \\ \Rightarrow F_{applied}=\mu mg=(0.1)(3)(10)\text{ N} \\ \Rightarrow F_{applied}=3N \end{gathered}$

Result: Applied force is 3N.