Answer
(a) 47.0 N
(b) 17.0 N
(c) 0 N
Work Step by Step
The normal force from the table plus the tension in the rope from the hanging weight will equal the weight of the box.
(a) $F_N+F_T = weight$
$F_N = weight - F_T$
$F_N = 77.0 ~N - 30.0 ~N$
$F_N = 47.0 ~N$
(b) $F_N+F_T = weight$
$F_N = weight - F_T$
$F_N = 77.0 ~N - 60.0 ~N$
$F_N = 17.0 ~N$
(c) The tension in the rope from the hanging weight is greater than the weight of the box, so the box will be pulled up in the air. Therefore, the normal force from the table on the box is 0.
