Simple Machines B/Compound Machines C Question Marathon

[fantasyfan]

I meant the distance from the middle of the base to the tip

[chinesesushi]

IMA of:
Pulley: number of strings supporting the mass
Lever: effort distance/load distance
Wedge: length/base width
Wheel and Axle: radius of wheel/radius of axle
Inclined Plane: Length of base/Height
Screw: Circumference/pitch

Then I think it's right for a wedge then. However, for the inclined plane I think it's wrong, and should be length of incline over height (http://hyperphysics.phy-astr.gsu.edu/hb ... ac.html#c1)

[fantasyfan]

Sorry, yes you are correct

[Algorhythmic]

What are some ways to increase the stability and balance of a first class lever?

[Algorhythmic]

More importantly, what can be changed to increase accuracy for calculations (much like the device portion of the competition)?

[SWAnG]

lighter material, reduce friction/contact of other materials

[Algorhythmic]

And for similar reasons, explain why using higher masses in calculations might increase your accuracy.

[SWAnG]

You lose sensitivity, as the ratio of the actual weights to the mass of your lever decreases. (When it's balanced, it's not as accurate this way). Think about it, when you have a heavier bar, it requires more force to move it then a lighter bar.

[treeling]

Here's a IMA question (Click to Show Hidden Text)

Suppose that the pulley in the below image is connected to something weighing 10 kg, and I need to pull on it with 9 N of force to hold it up. What's the efficiency? [img]http://02.edu-cdn.com/files/89501_89600/89569/file_89569.jpg[/img]

I'm not so sure about this but I'll give it a shot...

Answer (Click to Show Hidden Text)

IMA = (Force out of the machine)/(Force into the machine). 
So for this scenario, the Force into the machine would be 9N, I think. And the Force out of the machine would be 10kg * 9.8m/s/s = 98N. 
Therefore, the IMA = 98N/9N = 10.89? 
I feel like I need to use the visual somehow, but this is what I ended up doing... :?

I don't believe your answer is right.
IMA is Ideal Mechanical Advantage.
IMA is calculated by distance. Not force.
It your were calculating a MA with force that would be AMA (Actual Mechanical Advantage).

[SWAnG]

Is it 9?