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# Moments question watch

1. Hi

http://www.mei.org.uk/files/papers/J..._2013_June.pdf
Question 3 part 3 - MEI M2 June 13

I can do this question by taking moments about A but I dont get the same answer by taking moments about B.

i.e. M(B): Clockwise = anticlockwise
Ra x 0.8 = 60cos40 x 0.5 + 60sin40 x0.1
Ra = 33.55
vertically Ra x sin40 = 29.1N

But taking moments about A gives vertical support as 50.5N

2. (Original post by 123_qwerty)
Hi

http://www.mei.org.uk/files/papers/J..._2013_June.pdf
Question 3 part 3 - MEI M2 June 13

I can do this question by taking moments about A but I dont get the same answer by taking moments about B.

i.e. M(B): Clockwise = anticlockwise
Ra x 0.8 = 60cos40 x 0.5 + 60sin40 x0.1
Ra = 33.55
vertically Ra x sin40 = 29.1N

But taking moments about A gives vertical support as 50.5N

Link is broken but I'll give you a hint.

For angle moments, remember that the moment is the force multiplied by the perpendicular distance to the line of action of the force. Don't use the vertical/horizontal components of the force.

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