Question

A forward Horizontal force of 12N is used to pull a 240 N crate at a constant velocity across a horizontal floor. The coefficient of friction is?

Answer 1

$F=ma$

$a=0,\ v=const$

$F-F_f=0\to F_f=F\to \mu N=F\to\mu=F/N$

$\mu=\frac{F}{N}=\frac{F}{mg}=\frac{12}{240}=0.05$ . Answer