• Correct option is (C).
We know that the angle made by string is θ=
[tex]tan {}^{ - 1} ( \frac{a}{g} )[/tex]
where a is the acceleration of the frame in which the string is hanging in our case it is a trolley.
[tex]putting \: θ=37° \: or \: tan \: 37° = \frac{3}{4} [/tex]
[tex]we \: get \: a \: \frac{3g}{4} = \frac{30}{4} = 7.5 \: m/s^2[/tex]
[tex] \boxed{Force \: F=total \: mass \: of \: the \: system \: on \: which \: force \: is \: acting ×acceleration \: of \: the \: system=(8+2)×7.5=75 }[/tex]
[tex] \boxed{ so \: force \: is \: 75 \:N. }[/tex]
