What is the width of a rectangle given pressure, mass, and length of one side?

In summary, Pressure is 8 kPa, mass is 10 kg, length of one side of rectangle is 1.2 mFind width of rectangle
  • #1
rrrrrr
4
0

Homework Statement


Pressure is 8 kPa, mass is 10 kg, length of one side of rectangle is 1.2 m
Find width of rectangle

Homework Equations


P=F/A
N = kg * m * s^-2

The Attempt at a Solution


8kPa = (10kg * 10m/s) / (1.2 m * X m) /// X is the unknown width

8000Pa = 100N / 1.2X m^2

8000Pa * 1.2m * Xm = 100 N

X m = 100N / 9600 m * N/m^2

X m = 0.01 m

Wrong -- width won't be 0.01 m!
 
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  • #2
are you sure there is no given acceleration ?
 
  • #3
rrrrrr said:

Homework Statement


Pressure is 8 kPa, mass is 10 kg, length of one side of rectangle is 1.2 m
Find width of rectangle
Hi rrrrrr, Welcome to Physics Forums!

Your attempt at solution was logical given a likely interpretation of the given information in the problem statement, yet you claim that the answer you arrived at was wrong. Perhaps there's something missing from the problem statement that could shed light on this?

While we can guess at a likely scenario, it would be better if you could provide explicit detail so there's no confusion. Always endeavor to make your statement of the problem as clear and complete as you can.
 
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  • #4
Mevludin Licina said:
are you sure there is no given acceleration ?
Thank you for responding - there was nothing about acceleration.
 
  • #5
What is your basis for saying that the width cannot be 0.01 m? You must have more information of some kind...
 
  • #6
gneill said:
Hi rrrrrr, Welcome to Physics Forums!

Your attempt at solution was logical given a likely interpretation of the given information in the problem statement, yet you claim that the answer you arrived at was wrong. Perhaps there's something missing from the problem statement that could shed light on this?

While we can guess at a likely scenario, it would be better if you could provide explicit detail so there's no confusion. Always endeavor to make your statement of the problem as clear and complete as you can.

Thank you for responding. The question is from a test in an introductory physics course in 9th grade. What we wrote here is our guess at how to solve it.
The whole question just read that "A body of rectangular shape applies to a surface a pressure of 8kPa. The mass of the body is 10 kg and its length is 1.2 m.
A) What is the width of the body?
B) How will the pressure that the body exerts on the surface change if the width of the body is doubled?
 
  • #7
rrrrrr said:
Thank you for responding. The question is from a test in an introductory physics course in 9th grade. What we wrote here is our guess at how to solve it.
The whole question just read that "A body of rectangular shape applies to a surface a pressure of 8kPa. The mass of the body is 10 kg and its length is 1.2 m.
A) What is the width of the body?
B) How will the pressure that the body exerts on the surface change if the width of the body is doubled?
Okay! That's a much better problem statement :approve:

With that information it seems that your solution to part (A) for the width is fine.
 
  • #8
gneill said:
Okay! That's a much better problem statement :approve:

With that information it seems that your solution to part (A) for the width is fine.
Thank you very much. We weren't sure of the result.
 

1. What is pressure and how is it measured?

Pressure is the force exerted per unit area. It is measured in units of pascals (Pa) or newtons per square meter (N/m2). Pressure can also be measured in other units such as atmospheres (atm) or pounds per square inch (psi) depending on the context.

2. How is force related to pressure?

Force and pressure are directly related. The greater the force applied to a surface, the greater the pressure exerted on that surface. This means that as force increases, pressure also increases, assuming the area remains constant.

3. Can pressure be applied to an area without the presence of force?

No, pressure cannot exist without a force acting on an area. Pressure is a result of the force distributed over a specific area. Without a force, there is no pressure.

4. How does area affect pressure?

The larger the area over which a force is applied, the lower the resulting pressure will be. This is because the same amount of force is spread out over a larger area, resulting in a lower pressure. Conversely, a smaller area with the same amount of force will result in a higher pressure.

5. What are some real-life examples of pressure, force, and area?

Some common examples of pressure, force, and area include:
- The pressure exerted by a person standing on the ground is their weight (force) divided by the area of their feet in contact with the ground.
- The force of a car's tires on the road creates pressure that allows the car to move.
- In a hydraulic lift, a small force applied over a small area can lift a heavy object by creating a larger force over a larger area.
- In a balloon, the air inside exerts a force on the walls of the balloon, creating pressure that keeps it inflated.
- The pressure of a gas inside a container is a result of the force of the gas molecules colliding with the walls of the container over a specific area.

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