Which of the following is the reason a wedge is used in a knife?
A. increases the effort force
B. decreases the effort force
C. changes the direction of the effort force
D. decreases the resistance force

Question

Which of the following is the reason a wedge is used in a knife?
	A.	increases the effort force
	B.	decreases the effort force
	C.	changes the direction of the effort force
	D.	decreases the resistance force

anonymous · Answer

The reason for the wedge is it overcomes the resistance of materials to separate by transferring the force exerted against the material into two opposing forces normal to the faces of the blade.

kainui · Answer

Let's look at a simple equation for pressure.

$$Pressure = \frac{Force}{Area}$$

So if I push you I'm using a force and exerting it over the surface area of my hand. So that is a pressure. Now imagine me poking you with a pencil. The surface area went down from the size of my hand to the size of a very small tip. So that means the pressure will go up since the denominator getting smaller makes a number larger. Play with the fraction a little to see. But keep in mind the Force I applied in both cases was the same.

So by this you can see that to apply the same pressure you need less force for a smaller surface area. Does that make sense? Try to understand, and you will understand. =)

anonymous · Answer

But what one is it? @Kainui im trying to understand but its confusing