What is the tension in the upper string, physics, Basic Statistics

Question: The weights shown in the figure are in equilibrium. It consists of objects held by vertical strings. The object 3 weighs 1.4 N. The horizontal bars are identical, uniform and each weighs 0.5 N. What is the tension in the upper string?

 

1307_tension.png

Given that the weight of the object 3, W3 = 1.4 N The lower rod is in equilibrium. It means the net force and the net torque (i.e., moment of forces) acting on it is zero. The moment of the weights of object 2 and 3 are equal in magnitude

and opposite in direction (counterclockwise for W2 and clockwise for W3). The weight of this rod (W = 0.5 N) does not produce any torque about the point of suspension as it coincides with the center of gravity of the rod. Hence, from moment equation,

W2xL/2  - W3XL/2 = 0 

This gives, W2 = W3 = 1.4 N

Tension in the string connecting the upper and lower rods is given by T1 = W2 + W + W3 = 1.4 + 0.5 + 1.4 = 3.3 N (it follows from the fact that net force = 0)

The upper rod is also in equilibrium. It means the net force and the net torque acting on it is also zero. The upper rod is not suspended from its center of gravity. Hence, the weight of this rod (W = 0.5 N) also produces a counterclockwise torque about the point of suspension. The two points are different for this rod. Tension T1 acts downward on this rod and hence produces

clockwise torque on the upper rod.

The distance of the center of gravity from the point of suspension = L/2 - L/3  = L/6

Now, from moment equation

W1X2L/3 + 0.5XL/6 -T1XL/3 = 0

W1 = 1.525 N

Now, the tension in the upper equation

T2 = W1 + W + T1 = 1.525 + 0.5 + 3.3 = 5.325 N (it follows from the fact that net force = 0)

Posted Date: 2/26/2012 11:07:03 PM | Location : United States







Related Discussions:- What is the tension in the upper string, physics, Assignment Help, Ask Question on What is the tension in the upper string, physics, Get Answer, Expert's Help, What is the tension in the upper string, physics Discussions

Write discussion on What is the tension in the upper string, physics
Your posts are moderated
Related Questions
things to be investigate in mode

Capital outlays A budgetary, financial reporting term to end out the expenditures for the acquisition of: addition to:, chief repair of capital assets intended to advantage prospe

Obligations showing the responsibility to pay for solutions or products that have been suffered or obtained but not compensated for by the end of the sales interval.

What is prime cost? Primary price is the combination of a manufactured item's expenditures of immediate materials and immediate labor. In other words, prime price represent

could you please tell meaning of credit and debit notes in terms of intercompany transactions.

Suppose that permanent income, YP (t) is calculated as the average of disposable income (YD t ) over the past 5 years, that is: YP (t) = 0.2(YD t + YD t-1 + YD t-2 + YD t-3

A paper mill produces two grades of paper viz., X and Y. Because of raw material restrictions, it cannot produce more than 400 tons of grade X paper and 300 tons of grade Y paper i

what is variable mean

Choose a topic that interests you that you can explore either with the 2006 GSS. You should have one primary "dependent" variable that you are interested in (Y). This variable shou