Answer
a) +6 N
b) -24 N
c) -9.0 N
Work Step by Step
a) $F_{net}$
= ma
= 3 x 5
= 15 N
$F_{net}$
= $F_{1}$ + $F_{2}$
15 = 9 + $F_{2}$
$F_{2}$ = +6 N
b) $F_{net}$
= ma
= 3 x -5
= -15 N
$F_{net}$
= $F_{1}$ + $F_{2}$
-15 = 9 + $F_{2}$
$F_{2}$ = -24 N
c) $F_{net}$
= ma
= 3 x 0
= 0 N
$F_{net}$
= $F_{1}$ + $F_{2}$
0 = 9 + $F_{2}$
$F_{2}$ = -9 N
