Unit 1 Flashcards
1
Q
Density
A
Density = Mass / Volume
2
Q
Uptrust
A
- Weight of fluid displaced (Archimedes principle)
- Upthrust = g · volume (of object / fluid displaced)· density (fluid)
3
Q
Stoke’s Law
A
- F (N) = 6πηrv(ms
- Drag force = 6 · π · viscosity (Pas) · radius (m) · velocity(ms⁻¹)
- Object must be spherical
- Flow must be laminar
4
Q
Viscosity of fluids
A
- Liquids: As temperature increases, viscosity decreases
- Gases: As temperature increases, so does viscosity
5
Q
Laminar flow
A
- Fluid layers flow parallel to each other and don’t interact
- Constant speed
6
Q
Turbulent flow
A
- Fluid layers can cross over each other and turn at angles
- Eddy currents are formed
- Variable speed
7
Q
Hook’es law
A
- ΔF (N) = k (Nm⁻¹) · Δx (m)
- Proportionality between the force applied and extension of spring until the limit of proportionality
8
Q
Work done (Hooke’s Law)
A
- Area under graph
- Work done (J) = 1/2 · k · (Δx)²
9
Q
Stress
A
- Stress (Pa) = Applied froce (N) / Cross-sectional area (m²)
- A measure of the force in the cross-sectional area of a sample
10
Q
Strain
A
Strain = extrension (m) / original length (m)
- Measure of extension/compression of a sample in rearliton to original size
11
Q
Young modulus
A
Young modulus (Pa) = stress (Pa) / strain
- Measure of the stiffness of a material
12
Q
Thermal transfer of energy
A
- The thermal energy released when unloading a spring
- Work done (load) - Work done (unload)
13
Q
Elastic deformation
A
- Sample returns to original extension after force removed
14
Q
Plastic deformation
A
- Sample does not returns to original extension after force removed
15
Q
2 identical springs in series
A
- Overall k, half of k of single spring
- Double the extension with same load
