Question

2. What applied horizontal force is required to accelerate a 5 kg box along a horizontal surface with an acceleration of 2 m/s2 if the coefficient of friction is 0.15?

Answer 1

Given:

$m=5\:\rm kg$

$a=2\:\rm m/s^2$

$\mu=0.15$

The Newton's second law says

$$ma=F-F_f$$

$$ma=F-\mu mg$$

Hence, the requared force

$$F=m(a+\mu g)=5*(2+0.15*9.8)=17.4\:\rm N$$