Required Recall (from all topics) Flashcards
PH1. State the seven base quantities and their units.
Distance (meters, m) Time (seconds, s) Luminous Intensity (Candela, Ca) Mass (kilograms, kg) Current (Amperes, A) Temperature (Kelvin, K) Amount of Substance (moles, mol)
PH2. Define and state the units for every quantity listed on the formula sheet
Force (Newtons, N) Energy (Joules, J) Power (Watts, W) Potential Difference (Volts, V Resistance (Ohms, Ω) Charge (Columns, C) Power of Lens (Dioptres, D) Frequency (Hertz, Hz)
PH3. State equations to calculate areas, circumferences, surface areas, volumes of regular objects
Cuboids:
Spheres:
Cylinders:
PH4. State equations to calculate areas, circumferences, surface areas, volumes of regular objects
Cuboids:
Area = w x h
Volume = w x h x d
Circles:
Circumference = 2πr
Area = πr²
Spheres:
Area = 4πr²
Volume= ⁴/₃πr³
Cylinders:
Surface area = 2hπr + 2πr²
Volume = 2πr²h
ME1. State the definitions for scalar and vector quantities and give examples of each
Scalar Quantities only have magnitude.
Eg. mass, distance, speed
Vector Quantities have a magnitude and direction.
Eg. weight, displacement, velocity.
ME2. Label the quantities shown by the slopes and areas of distance-time, velocity-time, and acceleration-time graphs
Distance-time graph:
Slope - Speed
Area - n/a
Velocity-time graph:
Slope - Acceleration
Area - Displacement
Acceleration-time graph:
Slope - n/a
Area - Change in Velocity
ME3. Resolve a vector into two components at right angles to each other by calculation.
100N force, 50ᵒ from horizontal.
Y: 100Sin(50) = 76.6N
X: 100Cos(50) = 64.3N
ME4. State Newton’s Laws of motion
- An object at rest will remain at rest unless acted on by an unbalanced force.
An object in motion will remain in motion unless acted on by an unbalanced force. - The acceleration of an object is directly proportional to the resultant force acting on it, and inversely proportional to its mass.
- Every force has an equal, but opposite reaction force.
ME5. State the properties of pairs of forces in an interaction between bodies
- Acting on the same objects.
- In opposite directions.
- With the same magnitude.
- And the same type of force.
ME6. State the principle of conservation of linear momentum
The total momentum of an object before an event is equal to the total momentum of an object after momentum if linear momentum is conserved.
ME7. State the definition of ‘the moment of a force’
The turning effect of a force.
ME8. State the principle of conservation of energy
Energy cannot be created or destroyed only transferred from one object to another.
EC1. State the definition for current
The rate of flow of charge.
EC2. Derive the equations for combining resistances in series and parallel
The current through each resistor in series is the same: Iₜ = I₁ = I₂ = I₃
The total potential difference across the resistors is the sum of the potential differences across the separate resistors: Vₜ = V₁+ V₂+ V₃
Vₜ = IR
IₜRₜ = IₜR₁ + IₜR₂ + IₜR₃
(÷ Iₜ)
The total resistance is the sum of separate resistors: Rₜ = R₁ + R₂ + R₃
===============================
The potential difference across each resistor in parallel is the same: Vₜ = V₁ = V₂ = V₃
The current in the main circuit is the sum of the currents in each of the parallel branches: Iₜ = I₁ + I₂ + I₃
Iₜ=V/R
Vₜ/Rₜ = V₁/R₁ + V₂/R₂ + V₃/R₃
÷ Vₜ
The total resistance can be found through using Rₜ⁻¹ = R₁⁻¹ + R₂⁻¹ + R₃⁻¹
EC3. Sketch current-potential difference graphs for ohmic conductors, filament bulbs, thermistors, and diodes
Google answer.
Ohmic Conductor:
- Straight line.
- Passing through the origin.
Filament Bulbs:
- S-shaped
- Centred through the origin.
Thermistors:
- Decreasing exponential.
Diode:
- At zero behind y-axis.
- Exponential growth.
EC4. State the definition of electromotive force (e.m.f.)
The e.m.f. of a source is the amount of energy it supplies to one coulomb of charge.
EC5. Draw and label a diagram of the structure of a metal
Google answer.
- Positive ions (bigger than electrons).
- Delocalised electrons (with a negative charge).
- Regular structure.
MA1. Draw diagrams to show laminar and turbulent flow
Google answer.
- at least 5 lines
Laminar:
- Lines don’t cross.
- Moving in the same direction.
Turbulent:
- Lines crossing over.
- Conflicting directions.
- Som looping back on itself.
MA2. State the conditions in which Stoke’s Law applies
- Small spherical objects.
- Moving at low speeds with laminar flow (or in the absence of turbulent flow).
- At constant temperature (viscosity is temperature dependent).
MA3. State the relationship between upthrust and displaced fluid
Archimedes’ principle:
When a body is totally or partially immersed in a fluid, it experiences an upthrust equal to the weight of fluid displaced.
MA4. Draw and label force-extension and force-compression graphs
- Where direct proportionality is obeyd (Hooke’s Law is applied)
- Point where direct proportionality ends (Limit of proportionality, Close to this is the elastic limit.).
- Point which the graph declines (Yield point)
- Elastic and plastic region labeled at the top.
-
MA5. Define the terms limit of proportionality, elastic limit, yield point, elastic deformation and plastic deformation, and label these on force-extension/compression graphs
Limit of proportionality:
The is the point beyond which Hooke’s law no longer applies
Elastic limit:
The maximum extent to which a solid may be stretched without permanent alteration of size or shape.
Yield point:
The point beyond which a material becomes plastic.
Elastic Deformation:
The material will return to its original shape when the deforming force is removed.
Plastic Deformation;
The material will remain deformed when the deforming force is removed.
MA6. Draw tensile or compressive stress-strain graphs
Slide 191.
MA7. Label the quantities shown by the slopes and areas of a force-extension graph
Force-Extension:
Slopes: Spring constant
Area: Elastic strain energy
