Question

Blocks A and B have weights of 44 N and 22 N, respectively. (a) Determine the minimum weight of block C to keep A from sliding if between A and the table is 0.20. (b) Block C suddenly is lifted off A. What is the acceleration of block A if 3 between A and the table is 0.15?

Answer 1

a)

T=22 N,

$N=\frac{T}{\mu _s}=110~N,$

W=110-44=66 N,

b)

$\begin{cases} T-\mu_k N=m_A a, \\ m_B g-T=m_B a; \end{cases}$

$a=\frac{9.8\cdot (22-0.15\cdot 44)}{66}=2.3 ~\frac{m}{s^2}.$