RP10 Radiation and Absorption

Question 1

outline the basic steps of the practical.

Answer 1

1. place a lenslie cube on to a heatproof mat and fill with hot water
2. use the infrared detector to measure the amount of radiation that is emitted from each side
3. draw a suitable chart to compare the results for each surface

Question 2

what is a leslie cube?

Answer 2

a cube with different textured surfaces used to demonstrate the differing radiation emitted. typically it has a matt white, a shiny silver/gold, a matt black and a shiny black side.

Question 3

why is a heatproof mat used?

Answer 3

boiling water is poured into the cube meaning the base can get hot and so a mat is used to protect the desk.

Question 3

what type of data is collected from this experiment?

Answer 3

the four different surfaces being measured produces categorical data.

Question 3

which surface would you expect to emit the most radiaiton?

Answer 3

the matt black surface since good absorbers of radiation are also good emitters. matt black surfaces are good emitters and poor reflectors.

Question 4

give an example of a chart that may be used to display the data.

Answer 4

a bar chart with radiation intenisty on the y-axis and the four surfaces on the x-axis.

Question 5

what type of radiation is being emitted?

Answer 5

infrared radiation, which is part of the electromagnetic spectrum.

Question 6

which surfaces would you expect to emit the least radiation?

Answer 6

the shiny surfaces, as they are good reflectors and poor emitters.

Question 7

wyhat piece of apparatus is useful when filling the cube and why?

Answer 7

a funnel since the opening is very small and it will reduce the likelihood of spillages.

Question 8

what safety precaution should be taken when using a leslie cube?

Answer 8

avoid handling it with bare hands when filled with boiling water since the cube will be very hot.