A 7 m bar is pivoted at 2 m from the left end. A force of 60 N is applied downward on the left end and a force of 20 N is applied downward on the right end. What are the clockwise and counter-clockwise moments, and which direction would the bar rotate?

Study for the ABSA 4th Class Power Engineer Test. Explore questions with hints and explanations. Get ready to ace the exam!

To determine the moments and the direction of rotation for the 7 m bar, we first need to calculate the moments produced by the forces acting on either end of the bar about the pivot point.

The bar is pivoted 2 m from the left end, meaning that the left section of the bar (where the 60 N force is applied) is 2 m from the pivot, while the right side (where the 20 N force is applied) extends 5 m from the pivot point to the right end of the bar.

To calculate the clockwise and counter-clockwise moments:

  1. Clockwise Moment: This is created by the 20 N force applied at the right end of the bar. The distance from the pivot to the point of force application is 5 m. The formula for the moment is:

[

\text{Moment} = \text{Force} \times \text{Distance}

]

Plugging in the values:

[

\text{Clockwise Moment} = 20 , \text{N} \times 5 , \text{m} = 100 , \text{Nm}

]

  1. **Counter-clockwise
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