1)calculate the pressure, expressed in pascals, that the brick exerting a force of 18N, and dimensions od 9.3cm x 5.5 cm.
I know that Pressure = force divided by the area. the answer I got was 0.4Pa.
Is this correct?
2) why is an ax more useful to use (in terms of pressure) than a hammer, when you want to chop wood?
Is it because an Ax is stronger and sharper, which makes it have more force on the wood?
I don't understand the question very well...
for #2.
the reason that a ax is more useful is because the pressure exerted is over a smaller area than with the hammer. The ax's blade is thin while the hammer's top is wider thus pressure is applied over a larger area so it's not as powerful.
example is when people can lay on a bed of nails. A person wouldn't be able to be on 1 nail since the pressure applied is much much greater. However when a person can lay on nails they lay on alot of nails together and thus the weight of the person is displaced over a large area. (force is reduced)
1) To calculate the pressure exerted by the brick, we need to divide the force by the area of contact.
Given:
Force = 18N
Dimension of the brick: 9.3cm x 5.5cm
First, we need to convert the dimensions to meters:
Length = 9.3cm = 0.093m
Width = 5.5cm = 0.055m
Now, calculate the area of contact:
Area = Length x Width
Area = 0.093m x 0.055m
Area = 0.005115m²
Finally, calculate the pressure:
Pressure = Force / Area
Pressure = 18N / 0.005115m²
Pressure ≈ 3517.35 Pa
So, the correct answer is approximately 3517.35 Pa, not 0.4 Pa.
2) When it comes to chopping wood, an ax is more useful than a hammer in terms of pressure because it combines strength and sharpness. The edge of an ax is specifically designed to concentrate force on a smaller area, allowing for greater pressure to be applied to the wood. This focused pressure makes it easier to split the wood compared to using a hammer, which has a larger, flat surface area that distributes the force over a larger area, resulting in lower pressure and less efficiency in chopping wood.
1) To calculate the pressure exerted by the brick, you are correct that you need to divide the force applied by the area over which the force is distributed. In this case, the force is given as 18N and the dimensions of the brick are 9.3cm x 5.5cm.
To calculate the area, you need to multiply the length by the width. So, the area is calculated as follows:
Area = length x width = 9.3cm x 5.5cm = 51.15 cm²
Now, you can calculate the pressure using the formula P = F/A, where P is the pressure, F is the force, and A is the area:
Pressure = 18N / 51.15 cm²
However, it's important to note that when calculating pressure, it's important to use consistent units. In this case, you should convert the area from cm² to m² to match the SI unit of pressure, Pascal (Pa).
To convert cm² to m², divide by 10,000 since there are 10,000 cm² in 1 m²:
Area in m² = 51.15 cm² / 10,000 = 0.005115 m²
Now, you can calculate the pressure:
Pressure = 18N / 0.005115 m² ≈ 3519 Pa
So, the pressure exerted by the brick is approximately 3519 Pa, not 0.4 Pa.
2) When comparing an axe and a hammer for chopping wood, the question is referring to the concept of pressure. Pressure is the force applied per unit area. In this case, an axe is more useful than a hammer when chopping wood because it typically has a sharper and narrower edge, which allows the force to be concentrated over a smaller area on the wood.
When you swing an axe, the narrow edge concentrates the force on a smaller surface area of the wood, resulting in higher pressure being applied. This higher pressure helps to cut through the wood effectively.
On the other hand, a hammer typically has a broader and flatter surface, which distributes the force over a larger area when striking the wood. This results in lower pressure being applied to the wood, which is less effective at chopping or cutting through it.
So, an axe is more useful in terms of pressure because it concentrates the force over a smaller area, allowing for more effective cutting or chopping.