hi

can someone give the answers to those 2 Q
especially the second one..
http://i.imgur.com/dksu5PV.jpg
the first Q ..i solved it but i want to check out
a) vi= 18.1
b) 8-7= 1 ??? (not sure)
the second Q
acceleration = 7m/s2
but (b) the T and (c) i couldn't solve

thanks

Question

hi 

can someone give the answers to those 2 Q 
especially the second one..
http://i.imgur.com/dksu5PV.jpg
the first Q ..i solved it but i want to check out 
a) vi= 18.1 
b) 8-7= 1 ??? (not sure)
the second Q
acceleration = 7m/s2 
but (b) the T and (c) i couldn't solve 

thanks

michele_laino · Answer

I think that the tension $\tau$, is such that:
$\tau=(m_1+m_2)\cdot a=(1+2) \cdot 7=...?$
furthermore the cord exerts the tension $\tau$ on the $1$ Kg block, so the interaction force between $1$ Kg block and $2$ kg block is a force whose module is equal to $\tau$