Answer
The work done by $T_1$ is -7920 J
The work done by $T_2$ is -4580 J
The work done by gravity is 12,500 J
Work Step by Step
We can find the work done by $T_1$ as;
$W = T_1\cdot d$
$W = T_1 ~d~cos(\theta)$
$W = (1830~N)(5.00~m)~cos(150^{\circ})$
$W = -7920~J$
The work done by $T_1$ is -7920 J
We can find the work done by $T_2$ as;
$W = T_2\cdot d$
$W = T_2 ~d~cos(\theta)$
$W = (1295~N)(5.00~m)~cos(135^{\circ})$
$W = -4580~J$
The work done by $T_2$ is -4580 J
We can find the work done by gravity as;
$W_g = F\cdot d$
$W_g = F ~d~cos(\theta)$
$W_g = (mg) ~d~cos(0^{\circ})$
$W_g = (255~kg)(9.80~m/s^2)(5.00~m)(1)$
$W_g = 12,500~J$
The work done by gravity is 12,500 J