pressure

Question 1

pressure def

Answer 1

it is a force acting per unit area

Question 2

formula of pressure

Answer 2

pressure (Pa) = force/area (N/m^2)
- force can be calculated with: W = mg

Question 3

factors affecting magnitude of pressure

Answer 3

1. force acting
2. area of contact

Question 4

formula for force of hydraulic press

Answer 4

F2 = F1 (A2/A1)
- A2 > A1, F2 > F1

Question 5

pascal’s law

Answer 5

if a pressure is applied to an enclosed liquid, the pressure is transmitted to all other parts of the liquid undiminished

Question 6

density def

Answer 6

mass per unit volume

Question 7

density formula

Answer 7

density (rho) = mass/volume

Question 8

determine density of liquid

Answer 8

1. place empty measuring cylinder on electronic balance and record mass, M1 g.
2. pour 50 cm^3 of liquid into measuring cylinder. record new mass reading, M2 g.
3. density = (M2-M1)/50

Question 9

determine density of irregular shaped object

Answer 9

1. place object on electronic balance and record mass, mg
2. pour 50 cm^3 of water into measuring cylinder
3. place object into measuring cylinder. ensure that object is totally submerged (increase water)
4. record new volume, V cm^3
5. density = M/(V-50)

Question 10

determine density of an irregular shaped object that floats on water

Answer 10

1. place object on electronic balance and record mass, m g.
2. pour 50 cm^3 of water into measuring cylinder
3. place 50 g mass into measuring cylinder. record new volume reading, V1 cm^3
4. take mass out and tie to object
5. place mass and object into measuring cylinder. ensure object is totally submerged
6. record new volume reading, V2 cm^3
7. density = m/(V1-V2)

Question 11

formula for pressure in liquids

Answer 11

pressure = height x density x gravitational field strength (hpg)

Question 12

total pressure of object in liquid

Answer 12

atmospheric pressure + hpg, height = depth below surface of liquid