Nagwa uses cookies to ensure you get the best experience on our website. Learn more about our Privacy Policy.

In this lesson, we will learn how to identify the conditions for a system of coplanar forces to be equivalent to a couple and find its moment.

Q1:

π΄ π΅ πΆ π· is a rectangle in which π΄ π΅ = 1 2 c m , π΅ πΆ = 6 c m and π is midpoint of π΄ π΅ . Forces of magnitudes 7 N, 2 N, 6 N, 18 N, 3 β 5 N, and 1 0 β 2 N are acting along οͺ πΆ π΅ , ο« π΄ π΅ , ο« π· π΄ , ο« πΆ π· , ο« π΄ πΆ , and ο« π πΆ respectively. If this system of forces is equivalent to a couple, find the norm of its moment.

Q2:

The sides of an equilateral triangle π΄ π΅ πΆ , taken the same way round, completely represent three forces with a drawing scale of 4 cm to 8 N. If the length of a side of the triangle is 24 cm, find the magnitude of the resulting couple, giving an exact answer in Nβ cm.

Q3:

π΄ π΅ is a rod having a length of 105 cm and negligible weight. Forces of magnitudes 214 N, 67 N, 115 N, and 176 N are acting on the rod as shown in the figure. Given that πΆ and π· are the points of trisection of π΄ π΅ , determine the algebraic sum of the moments of these forces about the point π΄ .

Donβt have an account? Sign Up