Trouble with a basic fluid force problem

AI Thread Summary
The discussion centers on calculating the pressure on a horizontal surface 4m underwater with an area of 2m^2. The initial calculation mistakenly used the force formula, resulting in 78,400 N, which is incorrect for pressure. The correct approach is to use the pressure formula, P = F/A, leading to a pressure of 39,200 N/m^2. The confusion arose from calculating force instead of pressure, highlighting the importance of understanding the distinction between these two concepts. This clarification emphasizes the need to divide the force by the area to obtain the correct pressure value.
Wyoming Physics
Messages
10
Reaction score
0
What is the pressure on a horizontal surface with an area of 2m^2 that is 4m underwater?

I tried to just use the formula: Force= (Density of water)(Area)(Depth)(gravity), plugging in the values Force=(1000kg/m^3)(2m^2)(4m)(9.8m/sec^2) and get 78400 N, when in reality the real answer is supposed to equal 39,200 N/m^2.
 
Physics news on Phys.org
I can confirm your answer. Maybe someone forgot a factor of 2?
 
Ahhh nevermind, I have been calculating the FORCE on the plate and not the PRESSURE on the plate which is P=F/A which would explain they I have to divide the force by 2.
 
Oh, good point. It also changes the units.
 
Thread 'Struggling to make relation between elastic force and height'

Thread 'Struggling to make relation between elastic force and height'

Hello guys this is what I tried so far. I used the UTS to calculate the force it needs when the rope tears. My idea was to make a relationship/ function that would give me the force depending on height. Yeah i couldnt find a way to solve it. I also thought about how I could use hooks law (how it was given to me in my script) with the thought of instead of having two part of a rope id have one singular rope from the middle to the top where I could find the difference in height. But the...
View full post »
Thread 'Voltmeter readings for this circuit with switches'

Thread 'Voltmeter readings for this circuit with switches'

TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
View full post »

Similar threads

Force acting on one side of a fluid
Replies
22
Views
1K
Fluids: Concept about Fluid Pressure in a relation with Force and Area
Replies
6
Views
3K
Doubt related to buoyant force and fluid thrust force
Replies
9
Views
2K
Calculating Force to Push Steel Rod Up 50 cm
Replies
24
Views
3K
How To Calculate The Force Of Water Exerted On A Full Tank
Replies
7
Views
3K
Fluid Mechanics Challenging Problem
Replies
10
Views
2K
Determine Force on 6ft Door Due to Water & Air Pressure
Replies
7
Views
2K
Fluid Mechanics, Particle Size, Bouyouncy Force
Replies
16
Views
2K
Find the Upward Force of a Boat with 6 People Aboard
Replies
11
Views
2K
Bernoulli equation / fluid flow / finding height
Replies
6
Views
3K

Hot Threads

Recent Insights

Back
Top