How far a cube sinks below the waterlevel

  • Thread starter Thread starter justinram22
  • Start date Start date
  • Tags Tags
    Cube
AI Thread Summary
The discussion revolves around a physics problem involving a wood cube with a density of 700 kg/m^3 floating in water. For part (a), the user successfully calculates the distance from the top of the cube to the water surface but struggles with part (b), which requires determining the mass needed to make the cube's top level with the water. The user attempts to apply the buoyancy equation but arrives at an incorrect mass of 27 kg, while the solution in the textbook states 8.9 kg. Additionally, the user inquires about the weight of a cube of water with the same dimensions, indicating confusion about the calculations. The thread highlights common challenges in understanding buoyancy and density in physics problems.
justinram22
Messages
3
Reaction score
0

Homework Statement


A wood cube .30m on each side has a density of 700 kg/m^3 and floats levelly in water. (a) What is the distance from the top of the wood to the water surface? (b) What mass has to be placed on top of the wood so that its top is just at the water level.


Homework Equations


I assume the buoyancy equation.


The Attempt at a Solution


I figured out part (a) no problem, but seem to be having difficulty with part (b).

I assume it has to be:
Density=(mass/volume)?
When i do that I get 18.9, where the back of the book says 8.9

Thanks guys so much! Hope once I actually get good at physics I can come back and help people similar to myself!
 
Physics news on Phys.org
How much would the wooden block weigh if its density was the same as the density of water?
 
Sorry, but I'm still lost?

So

1000=(mass/.027)
mass=27?

Thanks!
 
27 what?
 
27kg

Which is not what they had in the back of the book (they had 8.9).

Thanks You again!
 
How much does a cube of water weigh which is 0.30 m on each side?
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Buoyancy: Cube of Iron - solved this correctly?
Replies
1
Views
3K
Calculating Buoyancy Force & Length of Submerged Cube
Replies
11
Views
2K
Calculate the Mass of Ice cubes needed to cool a soft drink
Replies
10
Views
3K
Wooden Cube submerged length and the carry limit
Replies
4
Views
1K
Find the fractional increase in inertial mass when an ice cube melts
Replies
10
Views
2K
Multiple choice buoyancy problem
Replies
6
Views
2K
Buoyant Force and Archimedes' Principle
Replies
13
Views
3K
Finding the Density of a Floating Cube
Replies
8
Views
2K
How to Calculate Water Pressure on a Floating Cube?
Replies
4
Views
3K
Force on the bottom of the vessel containing a submerged cube
Replies
30
Views
3K

Hot Threads

Recent Insights

Back
Top