Avertical piston cylinder device contains a gas at an unknown pressure. if the outside pressure is 100kpa, determine a) the pressure of the gas if the piston has an area of 0.2m2. and a mass of 20 kg. assume g=9.81m/s2. b) what would the pressure be if the orientation of the device were changed and it were now upside down?

a)

b)

Explanation:

Let's consider the piston on the figure attached.

We know that the atmospheric pressure on this case is

We know that the Are of the piston is and we have also the mass

Part a

We want to find the pressure at the gas, so that means point 2, and we assume that the pressure on any point of the gas is constant and the same. So then we can find the pressure at point 2 like this:

And the force on this case is the weigth

And then we have:

Part b

For this case we want to find the pressure if the device were changed and now would be upside down. On this case we will have lower pressure than from part a and would be given by:

the equation above shows how temperature f, measured in degrees fahrenheit, relates to a temperature c, measured in degrees celsius. based on the equation, which of the following must be true?

a temperature increase of 1 degree fahrenheit is equivalent to a temperature increase of

5

9

degree celsius.

a temperature increase of 1 degree celsius is equivalent to a temperature increase of 1.8 degrees fahrenheit.

a temperature increase of

5

9

degree fahrenheit is equivalent to a temperature increase of 1 degree celsius.

a) i only

b) ii only

c) iii only

d) i and ii only

answer:

50 vo; ts

explanation: