RP10: Radiation and Absorption Flashcards
1
Q
What is the aim of this experiment?
A
- Investigate how the amount of infrared radiation absorbed or radiated by a surface depends on the nature of that surface.
2
Q
Describe how you can investigate how the amount of IR absorbed or emitted by a surface depends on the nature of that surface (method)
A
- Align the infrared detector with one side of the Leslie Cube, 20cm away from the
side, and take the initial temperature of the surface. - Heat one side of the Leslie Cube by pouring hot water onto the surface.
- Measure and record the temperature of the surface every 30s for five minutes.
- Rotate the cube and repeat the experiment for a different surface.
- Plot temperature (plot on y-axis, measured in ℃) against time (plot on x-axis,
measured in seconds) for each different surface.
3
Q
List some safety precautions
A
- Take care handling hot water, be careful not to scold yourself and mop up any water
spillages. - Avoid spilling water on any electrics of the infrared detector
4
Q
What is a Leslie cube?
A
- A cube with different textured surfaces used to demonstrated the differing radiation emitted
- Typically it has a matt white, a shiny silver/ gold, a matt black, and a shiny black side
5
Q
Why is a heatproof mat used?
A
- Boiling water is poured into the cube meaning the base can get hot
- Mat used to protect desk
6
Q
What type of data is collected from this experiment?
A
- Categorical data
7
Q
Give an example of a chart that may be used to display the data
A
- A bar chart with radiation intensity on the y-axis and the four surfaces on the x-axis
8
Q
Which surface would you expect to emit the most radiation?
A
- Matt black surface - good absorbers and emitters of radiation, poor reflectors
9
Q
Which surface would you expect to emit the least radiation?
A
- Shiny surfaces - good reflectors, poor emitters
10
Q
What piece of apparatus is useful when filling the cube and why?
A
- Funnel - opening is very small, so it will reduce the likelihood of spillages
