Answer to Question #234104 in Physics for Cat

Question

two masses 5kg and 2kg connected by a rope .The 5kg mass experiences a kinetic friction of 9.8N between it and the table. Determine the i) acceleration of the system ii) tension in the rope

Answer 1

Given:

$m_1=5\:\rm kg$

$m_2=2\:\rm kg$

$F_f=9.8\:\rm N$

The Newton's second law says

$$m_1a=T-F_f\\ m_2a=m_2g-T$$

So,

(i)

$$(m_1+m_2)a=m_2g-F_f\\ a=\frac{m_2g-F_f}{m_1+m_2}$$

$$a=\frac{2*9.8-9.8}{5+2}=1.4\:\rm m/s^2$$

(ii)

$$T=m_2g-m_2a=2*(9.8-1.4)=16.8\:\rm N$$