If M = 2.0 kg,what is the tension in string 1?
A)1.2 N
B)11 N
C)34 N
D)3.5 N
E)40 N

Question

If M = 2.0 kg,what is the tension in string 1? 
A)1.2 N 
B)11 N 
C)34 N 
D)3.5 N 
E)40 N

Quizplus · Accepted Answer

We can use Newton's second law to solve this problem. Since the object is in equilibrium, the net force acting on it is zero. This means that the upward tension force in string 1 is equal in magnitude to the downward gravitational force on the object:
T1 = M*g = 2.0 kg * 9.8 m/s^2 = 19.6 N
However, we also know that there is a horizontal force of 17 N pulling on the object to the right. This means that there must be a second tension force, T2, acting on the object to the left in order to maintain equilibrium. We can use the fact that the object is not moving horizontally to set up an equation for the forces in the horizontal direction:
T2 - T1 = 17 N
Substituting the value we found for T1, we get:
T2 - 19.6 N = 17 N
T2 = 36.6 N
Since we are looking for the tension in string 1 specifically, we choose option C, which is equal to T1.

If M = 20 Kg,what Is the Tension in String 1