Question

A $1kg$ block $B$ rests on a bracket $A$ of same mass as shown in figure. Constant forces $F_1=20N$ and $F_2=8N$ start acting at time $f=Q$. The distance of block $B$ from pulley is $50m$ at $t=0$. Determine the time (in s) when block $B$ reaches the pulley.

Answer 1

$M_B=1Kg=m_A$ $F_1=20N$

$F_2=8N$

$F_1-T^{\prime }=1a_{Ag}$ $T^{\prime }=2F_2$

$20-16=a_{Ag}$

$a_{Ag}=4m/s^2$

$F_2-ma=a_B$

$a_B=4m/s^2$

$50=\frac{1}{2}\ast 4\ast t^2$

$t=5sec$