Pressure And Density Flashcards
How do you find the density of a regular solid
- Find mass on a balance
- Met at the three sides-multiplied to find volume
- Density= mass\volume
How to find the density of a irregular shape
- Find the maths on a balance
- Find the volume by measuring the displacement of the water in a cylinder
How do you find the density of a liquid
- Find the mass of an empty cylinder
- Put in the liquid
- Measure the volume
- Find the mass of cylinder + liquid, subtract mass of cylinder
- Density =m/v
What is the equation for pressure
Pressure (N/cm2) = force(N) / area ( cm2,m2)
P=f/a
In the pressure equation, fourth is the weight of an object. How do you work out the weight of an object?
Weight (N) = maths (G) x 10
What is N/M2 commonly known as
Pascal (PA)
Pressure in fluids (fluids refer to liquids and gases). Explained the way they act in different directions
Pressure and fluids acts in all different direction equally
How does that affect pressure in fluids
Pressure in the fluid increases with depth
What is the equation to find the pressure at different depths of the fluid?
P=hdg (nb, density sign is funny p)
Pressure= depth X density of fluid X strings of gravity
Can only be In M, KG/M3, 10N/KG
To work out all the pressure that is acting on something, what must you add?
The atmospheric pressure (usually 101, 000)
What is a Manometer
It measures the pressure of the gas. One end is open to the atmosphere the other end is attached to the gas to be investigated
How would you work out the difference in pressure between the gas being investigated and the atmosphere
Change in pressure (left/right) = difference in height of water (metres) X density X gravity
What causes air pressure
When are particles collide with the surface, they rebound and moved in opposite directions
Each collision exerts a tiny force on the surface. There are so many particles colliding that overall they exert a significant force and hence a pressure on the surface
how can the price increase
More particles results in more collisions, therefore pressure increases. Hotair has faster moving particles, so the number of collisions per second increases, therefore pressure increases.
Great to frequency of collision= greater pressure
What is a barometer
Oh barometer is a device used to measure air pressure. The air pushes down on the liquid in the tub, forcing it to the tube. When the weight of the mercury in the tube balance is the force exerted by the air on the Mercury, The column of mercury settles down. If the app pressure goes up, the column of Mercury is taller
