All Junior Cert Science Revised Syllabus posts
• #### moments and centre of gravity Sarah2014

i have a test on Thursday and im screwed! what is the fulcrum of a door? is the door handle? in the experiment with the newtons and the ruler, is it balanced when they are further apart or closer together. thank you!

1. #### granners

In the experiment with the ruler, you multiply the distance from weight to generally the centre of the metre stick by the weight in N and do this to both and they should equal each other if the metre stick is balanced. I'm pretty sure the fulcrum of the door is the side of the door connected to the frame as the whole door turns at that point

2. #### Roberto Mane

Hi Sarah,the door handle is where the effort is applied but the fulcrum is located in the hinges of the door because this is the fixed point from which the door turns about.In the case of the ruler and newton weights,the exerted moments is larger the further you go from the fulcrum because the moment of a force=(F)(Distance from the fulcrum),where F=Force.In order for a lever to be balanced the total clockwise moments have to equal the total anticlockwise moments.Hope this helps.

3. #### Sarah2014

thanks so much guys this helped me loads :)

4. #### Me

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