Question

A 9.00-kg hanging object is connected by a light,inextensible cord over a light ,frictionless pulley to a 5.00-kg block that is sliding on a flat table. Taking the coefficient of kinetic friction as -.200, find the tension in the string

Answer 1

the arrow in brown shows the friction,

block m₂:

$m_2 g - T = m_2 a \\ 9 \times9.8 - T = 9a \;\;\; (1) \\ N - m_2 g = 0 \\ N = m2 g = 5 \times 9.8 = 49 \; N \\ f = μN \\ f = 0.2 \times 49 = 9.8 \;N$

block m₁:

$T - f = m_1a \\ T - 9.8 = 5a \;\;\;(2)$

solving 1 and 2:

$T = 37.8 \; N \\ a = 5.6 \;m/s^2$