Question

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

Answer 1

$$F_{appl}-F_{fr}=ma,$$ $$F_{appl}-\mu mg=ma,$$ $$F_{appl}=m(\mu g+a),$$ $$F_{appl}=5\ kg\cdot(0.15\cdot9.8\ \dfrac{m}{s^2}+2.0\ \dfrac{m}{s^2})=17.35\ N.$$