matter

Question 1

pressure formula

Answer 1

P=F/a

• pressure in Nm-2 / Pa (1 Nm-2 = 1Pa)
• force in N
• area of contact in m2
• as area increases, pressure decreases for constant force
• as force increases, pressure increases for constant area

Question 2

pressure depends on:

Answer 2

• the number of collisions per second between particles and side walls
• the force of the collisions

Question 3

pressure and volume

Answer 3

• pressure in inversely proportional to volume for a constant temp (when volume doubles, pressure halves)
• when volume decreases -> gas particles have less distance to travel between collisions with the container walls -> frequency of collisions increases (but force of each collision stays the same) -> pressure increases

Question 4

pressure and temperature

Answer 4

-pressure in directly proportional to temp for a constant volume (when pressure doubles, temp doubles)

Question 5

pressure volume formula

Answer 5

P1V1=P2V2

volume units don’t matter as long as they are the same on both sides e.g. both cm3 or L

Question 6

specific latent heat of vaporisation

Answer 6

• the energy required to change 1kg from liquid to gas without change in temp
• liquid -> gas then thermal energy is absorbed
• gas -> liquid then thermal energy is released

Question 7

specific latent heat of fusion

Answer 7

• the energy required to change 1kg from solid to liquid without change in temp
• solid -> liquid then thermal energy is absorbed
• liquid -> solid then thermal energy is released

Question 8

latent heat formula

Answer 8

Eh=mL

• heat energy in J
• mass in kg
• latent heat of vaporisation/fusion in Jkg-1

Question 9

density formula

Answer 9

p=m/v

Question 10

1gcm-3 =

Answer 10

1000kgm-3

Question 11

measuring volume

Answer 11

• solid cuboid: measure dimensions and calculate - l x b x h
• solid with irregular shape: fill a container with water, measure the volume of the water, place the sample in water, measure the new volume and subtract

Question 12

hydrostatic pressure (pressure of liquids) formula

Answer 12

hydrostatic pressure = hpg

• height in metres
• density in kgcm-3
• gravitational field strength in Nkg-1

Question 13

pressure across fluids

Answer 13

pressure is transmitted through fluids so:

pressure at X = pressure transmitted to Y

Question 14

how is an atom’s nucleus held together?

Answer 14

• protons and neutrons are held together in the nucleus by the strong nuclear force
• it is the strongest attractive force but only operates over extremely small distances