Question

finding tension between two blocks with friction

Answer 1

Tension is constant across the string.so
T - mg = ma (1) 
Mg - T = Ma (2), where M and m denote large and small mass respectively 

Add equations (1) and (2): 
g(M - m) = a(m + M) 
a = g(M - m)/(m + M) 

Also, T = m(g+a) = m*g(1+(M-m)/(m+M). 
Now plug the values! 
T = 1.00 kg * 10m/s^2 * (1 + (2.00 kg - 1.00 kg)/(2.00 kg + 1.00 kg)) 
= 10 kg m/s^2 * (4/3) 
= 13.3 N (to 3 significant figures) 
Note: I assumed that the values were to three significant figures. If the question was worded as written above the answer would just be 13N.

HOPE IT WILL HELP U:)