If α = 40° and the tension in string 2 is 30 N,determine M.
A)3.4 kg
B)3.6 kg
C)2.6 kg
D)4.9 kg
E)7.5 kg

Question

If α = 40° and the tension in string 2 is 30 N,determine M. 
A)3.4 kg 
B)3.6 kg 
C)2.6 kg 
D)4.9 kg 
E)7.5 kg

Quizplus · Accepted Answer

Using the equilibrium equation for forces in the vertical direction:
T1sinα - Mgsinθ - T2sinα = 0
T1sinα = T2sinα + Mgsinθ
T1 = T2 + Mgtanθ
M = (T1-T2)/g tan θ
M = (T1-T2)/(9.81 tan 40°)
M = (T1 - 30)/(9.81 x 0.839)
M = (T1 - 30)/8.21

Given T1 = 50 N
M = (50 - 30)/8.21
M = 2.43 kg

Therefore, the closest option is C) 2.6 kg.

If α = 40° and the Tension in String 2