Simple Machines B/Compound Machines C Question Marathon

[fantasyfan]

Three part question:
A) state the IMA formula of a wedge
B) solve for the IMA of a wedge whose vertices contain 45 degrees, 45 degrees, and 90 degrees
C) state why it is impractical to measure the AMA and efficiency of a wedge

[Sciolapedia]

Three part question:
A) state the IMA formula of a wedge
B) solve for the IMA of a wedge whose vertices contain 45 degrees, 45 degrees, and 90 degrees
C) state why it is impractical to measure the AMA and efficiency of a wedge

A. The formula is depth of penetration over width(separation of wedged surfaces)
B. The ratio is 1:1:root2 The height and width happen to be the 1 sides so 1/1= 1
C. Its impractical to measure AMA and efficiency because there is so much friction when the wedge is splitting apart the object. Most of the work is lost to friction and creates heat. The input force may be large, but the output force would only be a small portion of it so there's no point even measuring it. Efficiency is going to have the same reason since it equals AMA/IMA.

[fantasyfan]

A. The formula is depth of penetration over width(separation of wedged surfaces)
B. The ratio is 1:1:root2 The height and width happen to be the 1 sides so 1/1= 1
C. Its impractical to measure AMA and efficiency because there is so much friction when the wedge is splitting apart the object. Most of the work is lost to friction and creates heat. The input force may be large, but the output force would only be a small portion of it so there's no point even measuring it. Efficiency is going to have the same reason since it equals AMA/IMA.

All correct and very well stated except for part B which the answer is 1/2. In order to find the IMA of the wedge, you must first split it into two 45-45-90 triangles which share one side, the height. If you set the height to x, then due to the ratio you stated, one half of the base will also be x. There fore the width is 2x and the height is x making th IMA x/2x which equals 1/2.
Your turn

[Sciolapedia]

if the 3 vertices of the triangle are 45 45 and 90, then the wedge is a right triangle. The height would be the one opposite the 45 and the width would also be opposite the 45 so the ratio would be one. Though im probably making a dumb mistake somewhere .

Here's the next question:
What is a wheel and axle? Who discovered it? Give examples of wheel and axles.
Calculate the IMA of a wheel and axle with an outer radius of 5 and an inner radius of 3. Outer radius being where you apply the input force.

[madergaser]

Umm I'm pretty sure about the IMA part, but the history part, that is just a guess

[hide]1. Heron of Alexandria
2. the IMA is the radius of the wheel over the radius of the axle, so IMA = 5/3[/hide]

[JustDroobles]

Sciolapedia, I think you are imagining a different wedge than Fantasyfan. Although I guess you aren't incorrect, often a wedge is imagined as an isosceles triangle pointing towards the direction of travel.
[hide]In this case, the 90 degree point would be pointing in the direction of travel, so the output distance would the side opposite the 90 degrees and the input distance would be the altitude to that side. So that should give you 2/1=1.[/hide]

[Sciolapedia]

The ima is correct. The answer to the wheel and axle,I think, is that the inventor was too long ago so it wasn't recorded. However u still didn't answer the two other questions.

[chinesesushi]

The ima is correct. The answer to the wheel and axle,I think, is that the inventor was too long ago so it wasn't recorded. However u still didn't answer the two other questions.

Answer? (Click to Show Hidden Text)

According to the 2nd passage here ([url]http://en.wikipedia.org/wiki/Wheel_and_axle[/url]), Heron of Alexandria [b]identified[/b] the wheel and axle as a simple machine in the form of a windlass. When it was discovered, I think you are more correct in that area. All in all, it's a very vague question, and I doubt they'll put a question where the answer is "no one knows". The wheel and axle is a simple machine consisting of a wheel connected to an axle, which have a larger and smaller diameter/radius/circumference respectively. As a force is applied to turn either the wheel or the axle, the force is transferred from one to the other, either increasing the force over a smaller distance (turning of wheel) or decreasing the force over a larger distance (turning of axle). Examples of applications of the wheel and axle include screwdrivers, doorknobs, steering wheels, wheels on a car, etc.

[Sciolapedia]

Really nice
good job

your turn

[chinesesushi]

In a common nail clipper, what two simple machines are used to form the compound machine? If either one is a lever, please indicate the class of lever.