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

[rrrrrr]

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!

 

[meyol99]

are you sure there is no given acceleration ?

 

[gneill]

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.

 

[rrrrrr]

are you sure there is no given acceleration ?

Thank you for responding - there was nothing about acceleration.

 

[gneill]

What is your basis for saying that the width cannot be 0.01 m? You must have more information of some kind...

 

[rrrrrr]

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?

 

[gneill]

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

With that information it seems that your solution to part (A) for the width is fine.

 

[rrrrrr]

Okay! That's a much better problem statement

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.