Question

A block of mass 5.00 kg rests on a horizontal surface where the coefficient of kinetic friction between the two is 0.200. A string attached to the block is pulled horizontally, resulting in a 3.00 m/s² acceleration by the block. Find the tension in the string. (g = 9.80 m/s²)

Answer 1

Let's apply the Newton's Second Law of Motion:

$$F_T-F_{fr.}=ma,$$ $$F_T-\mu_kmg=ma,$$ $$F_T=m(\mu_kg+a),$$ $$F_T=5.0\ kg\times(0.2\times9.8\ \dfrac{m}{s^2}+3.0\ \dfrac{m}{s^2})=24.8\ N.$$