Required Practicals Flashcards
What is the aim of RP1 - determining specific heat capacity?
To determine the specific heat capacity of a 1kg block of aluminium using a circuit.
What is the Equipment needed for RP1?
- Aluminium (1kg)
- Ammeter
- Voltmeter
- Wires
- Heater
- Stopwatch
- Themometer
- Power Pack
What is the method for RP1?
1) Connect the aluminiuk block to an ammeter, voltmeter, heater and power pack in a circuit.
2) Measure the voltage, current and temperature.
3) Use the equation E = Pt (E = I x V x t) to calculate the energy. *Power = I x V, I = current, V = voltage. The t (time) should be recorded with a stopwatch.
4) Then do c = E / m x change in temp
You should now have the specific heat capacity of the 1kg block of aluminium.
What is the aim of *RP2 - Insulators?
To use different different materials with different thicknesses to investigate their effectiveness as insulators.
They will each have to insulate boiling water for a certain time.
What is the Equipment needed for RP2? What are the variables?
Independent Variable - Insulator
Dependent Variable - Temperature of the water (°C) at certain intervals
Control Variables - volume of water, time for insulator to work (2 minutes), area of coverage over the top of the beaker to, resolution (.0°C), initial tenperature of the water.
Equipment:
- Water
- Beaker
- Insulators (newspaper, foil, cardboard, bubble wrap)
- Thermometer
- Heat proof mat
- Kettle
- Elastic band
- Stopwatch
What is the method for RP2?
1) Heat a set volume of water in a kettle.
2) Pour into beaker.
3) Attach insulator and record temperature change at certain intervals OR measure the initial and final temperature change.
4) Repeat with different insulators.
What was the conclusion in RP2?
The thicker the insulator, the less temperature change (heat loss).
The lower the thermal conductivity, the less temperature change (heat loss).
Insulators must be thick and have a low thermal conductivity.
What is the aim for *RP5 - Density?
To record and calculate the masses and volumes of objects and to calculate their densities.
Also to observe Archimides’ principle and the relationship between density and floating.
What is the Equipment for RP5?
- Eureka can
- Water
- Objects
- Balance
- Ruler
- Calculator
- Measuring cylinder
- Tray
What is the method for RP5?
1) Record the mass of each object using a balance.
2) Record the volume - measure or place in eureka can and record the volume of water displaced.
3) Use the density equation (p = m / v)
4) Record in a suitable table.
What is the conclusion for RP5?
Mass is directly proportional to density. Volume is inversely proportional to density.
If density is less than 1g/cm^3 - object will FLOAT.
What is the aim of RP6 - force and extension of a spring?
To measure the extension of a spring with different forces/weights and to plot a force-extension graph.
What is the equipment needed for RP6?
- Spring with wooden pointer attached to bottom - must record original position (no added masses).
- Set of 1N (0.1kg) masses.
- Clamp & Clamp Stand (edge of table)
- 1m rule - must be vertical for accurate readings.
- Heavy weight - to keep the clamp stand stable.
What is the method for RP6?
1) Clamp the stand to the bench.
2) Hang the spring to the clamo stand.
3) Record the original length of the spring (no added masses).
4) Add masses on at set intervals. Remove the masses.
5) Record the extension length each time when the masses are added and removed.
6) Plot a graph - X-axis = Weight (N), Y-axis = Extension (m), Gradient = Spring Constant (k)
What is the conclusion for RP6?
The extension of a spring is directly proportional to the force applied, as long as the limit of proportionality is not exceeded.
MATCHES HOOKE’S LAW.
Force = spring constant x extension F = kx
Graph:
-If limit of proportionality is exceeded, the graph becomes non-linear (curves up).
What is the aim of RP7 - acceleration of car with different forces?
To investigate Newton’s second Law (F = ma) by investigating how acceleration is affected by:
- varying the force with a constant mass. OR
- varying the mass with a constant force.
What is the equipment needed for RP7?
- A trolley/toy car - place masses on car for varied mass, or on string for varied force.
- Masses - e.g 100g (0.1N) - provide the force
- String & Pulley
- motion sensor / light gate with computer
- Bench/Table
- Stopwatch Timer + Ruler (Distance Markers) OR light gate and interface
What is the method for RP7?
1) Attach trolly to piece of string. Attach string to a pulley over the end of a bench.
2) Attach the other end of the string to masses. Let go of the trolley at the starting point. The car will accelerate along the bench.
3) Set up light gate and interface OR be ready with stopwatch and distance markers.
4) Read the acceleration value off the interface OR Record the time for the trolley to pass each distance marker.
5) Repeat with more or less masses:
- vary the mass = place or remove masses onto or from the trolley itself - keep masses on pulley system the same.
- vary the force = place or remove masses onto or from the pulley system - no masses on trolley.
6) Record results in suitable table.
What is the conclusion for RP7?
Force is directly proportional to acceleration - more masses on the pulley system = faster the acceleration.
Mass is inversely proportional to acceleration - more masses on the car (same on pulley) = slower the acceleration.
F = ma re-arranged: a = F / m -> bigger force means bigger acceleration. Bigger mass means smaller acceleration.
What is the aim of RP8 - waves?
To use a ripple tank to measure the frequency and wavelength of water waves.
And to use these measurements to calculate the wavespeed.
What is the equipment needed for RP8?
- Ripple Tank
- Lamp
- Power Pack
- Water
- White Paper
- Vibrating Bar
- Mobile Phone / iPad to record images.
What is the method for RP8?
1) Electricity makes the vibrating bar vibrate. This creates waves across the surface of the water.
2) Above the tank is a lamp and below the tank is white paper.
3) Measure the wavelength:
- Freeze image of waves.
- measure distance between first and last wave.
- divide by the total number of waves to find the wavelength of one wave.
4) Measure the frequency:
- place a timer next to the paper.
- record the number of waves passing a fixed point in one second
- video it and watch it in slow motion
5) Calculate wavespeed:
wavespeed = frequency x wavelength
Alternative method:
- Speed = Distance / Time
- Select one wave and record how long it takes for one wave to travel the length of the tank.
- Always say the equipment used to get the measurements.
What is the aim of RP10 - infrared radiation?
To investigate how the properties of a surface affect the amount of infrared (heat) absorbed or radiated by the surface.
What is the equipment needed for RP10?
- 4 equal containers
- Matt black surface
- Shiny black surface
- White surface
- Shiny metallic surface
- Water
- Kettle
- Themometer
- Cardboard cover
- Heat-proof mat
- Stopwatch
What is the method for RP10?
1) Place boiling water in each container.
2) Place a different surface around each container.
3) Record the temperature change every 30 seconds for 20 minutes (1200 seconds).
4) Record the data in a table.
What is the conclusion for RP10?
- Matt Black cooled down the fastest, from the highests starting temperature.
- Shiny metallic cooled down the slowest, from the lowest starting temperature.
Matt black = best absorber and emitter of infrared.
Shiny metallic = worst absorber and emitter of infrared.
Order:
1) Matt black
2) Shiny black
3) White
4) Shiny metallic
What is the aim of *RP9 (a) - Refraction through a perspex block?
Investigating the refraction of light through a glass and/or perspex block to:
- predict the refraction of light in other substances.
- compare refraction to reflection in terms of angles.
- compare refraction to reflection in terms of material.
What is the equipment needed for RP9 (a)?
- Ray Box - turn it off when not being used - gets hot.
- Power Pack
- Light filter - creates a sharp ray of light.
- A3 Plain White Paper
- Perspex Block and/or Glass Block - to act as the boundary
- Pencil, Ruler, Rubber - for the ray lines
- Protractor - measure the angles
What is the method for RP9 (a)?
1) Place the perspex or glass block in the centre of the paper.
2) Draw pencil lines around the perspex block.
3) Create a normal to the block (through the middle of the rectangle)
4) Measure 5 angles from the normal (10°, 20°, 30°, 40°, 50°).
5) Darken the room. Switch on the ray box and direct *THIN incidence rays of light along those lines.
6) Observe, measure and record the angles of refraction - measure from the centre of the ray.
*rays need to be THIN to reduce uncertainty (the distance from the true value)
What is the conclusion for RP9 (a)?
If light moves from fast to slow, the refracted ray will be closer to the normal (F—>st).
If light moves from slow to fast, the refracted ray will be away from the normal (S—>fa).
Sin (i°) / Sin (r) = constant (for the same material)
Sin (i°) / Sin (r) = refractive index (n)
IMPORTANT:
- Angles of incident and reflection do not depend on the material (could be glass or perspex).
- But, the angles of refraction will be different due to different refractive index’s.
What is the aim of *RP9 (b) - Transmission of light through different surfaces?
To investigate whether surfaces are opaque, translucent or transparent.
What is the equipment needed for RP9 (b)?
- Light source
- Different materials.
What is the method for RP9 (b)?
1) Shine a light through different surfaces and note whether the object is opaque, translucent or transparent.
What is the conclusion for RP9 (b)?
Opaque objects absorb all the light that reaches it.
Translucent objects let light pass through, but scatter or refract the light inside.
Transparent objects let light pass through without any scattering or refraction inside.
