When the masses of the blocks are doubled and the force applied is constant, the tension in the string will be the same.
The given parameters:
The acceleration of the blocks is calculated as follows;
[tex]a = \frac{F}{m + 2m} \\\\a = \frac{F}{3m}[/tex]
The tension in the string is calculated as follows;
[tex]T = ma\\\\T = m(\frac{F}{3m)}\\\\T= \frac{F}{3}[/tex]
When the masses of the blocks are doubled and the force applied is constant;
[tex]a = \frac{F}{2m + 4m} \\\\a = \frac{F}{6m}[/tex]
The new tension in the string is calculated as follows;
[tex]T_2 = ma\\\\T_2 = (2m) (\frac{F}{6m} )\\\\T_2 = \frac{F}{3} = T[/tex]
Thus, when the masses of the blocks are doubled and the force applied is constant, the tension in the string will be the same.
Learn more about tension in string between two blocks here: https://brainly.com/question/13539944