Answer:
The tension in the string is equal to Ct
And the time t0 when the rension in the string is 27N is 3.6s.
Step-by-step explanation:
An approach to solving this problem jnvolves looking at the whole system as one body by drawing an imaginary box around both bodies and taking summation of the forces. This gives F2 - F1 = Ct. This is only possible assuming the string is massless and does not stretch, that way transmitting the force applied across it undiminished.
So T = Ct
When T = 27N then t = T/C = 27/7.5 = 3.6s