A small object of mass m m\,m is held in equilibrium by two light inextensible strings. The tension forces exerted by the strings on the object are represented by the vectors T1\mathbf{T}_1T1 and T2\mathbf{T}_2T2, and the gravitational force (weight) acting on the object is represented by the vector W\mathbf{W}W, as shown in the free-body diagram below.
Which vector equation correctly describes the equilibrium condition for the object?
T1+T2+W=0\mathbf{T}_1 + \mathbf{T}_2 + \mathbf{W} = \mathbf{0}T1+T2+W=0
T1+T2−W=0\mathbf{T}_1 + \mathbf{T}_2 - \mathbf{W} = \mathbf{0}T1+T2−W=0
T1+T2=W\mathbf{T}_1 + \mathbf{T}_2 = \mathbf{W}T1+T2=W
∣T1∣+∣T2∣=∣W∣|\mathbf{T}_1| + |\mathbf{T}_2| = |\mathbf{W}|∣T1∣+∣T2∣=∣W∣