Pressure

Question 1

What is pressure and whats the equation

Answer 1

Pressure is the force per unit

Pressure= force/ area

Force being (N)
Area being (m)
Pressure being (pa)

Question 2

How does pressure vary due to the amount of force and area

Answer 2

If a force is spread over a large area it will result in a small pressure
If it is spread over a small area it will result in a large pressure

Question 3

Pressure in liquids

Answer 3

When an object is immersed in a fluid, the fluid will exert pressure, squeezing the object
The pressure of a fluid on an object creates a force normal (at right angles) to the surface

The pressure of a fluid on an object will increase with:
- Depth within the fluid
- Increased density of the fluid

Question 4

Equation for calculating pressure in liquids

Answer 4

P = pgH

P = change in pressure (pascals)
p = density of the liquid (kg/m^3)
g = gravitational field strength (10n)
H = change in height (depth) (m)

Question 5

Pressure of gas

Answer 5

Change of momentum, of particles striking the walls of an container exerting a force

Factors affecting the pressure of gas
- higher temp
- lower volume
- moles (how many particles)

Boyles law - if the temp and mass of the gas is constant then the volume is inversely proportional to the applied pressure
- basically when the volume decreases pressure increases as there is less distance to travel to when hitting the sides

1atm = 1L, 2atm = 0.5L (if we double one variable we cut one in half to keep it inversely proportional

Charles laws - if we heat up a balloon the pressure will go up as particles are moving faster but in order to keep pressure constant we have to increase the volume too therefore volume and temperature is directly proportional to pressure

Must use kelvin when working with gas laws

Da Ideal gas law, this equation is used to figure out any of our constants eg: volume, moles, temp and pressure

P1V1 = P2V2

Remember you can also use the other laws to find it