Practicals

Question 1

How can you investigate absorption with the melting wax trick

Answer 1

The amount of infrared absorbed by different materials also depends on the surface

Question 2

Practical for Investigating IR absorption

Answer 2

1 ) Place a bunsen burner on a heat proof mat
2 ) stick a metal ball to each identical side of the metal plates with hot candle wax
3 ) Leave candle too coll.The wax will harden and hold the ball in place.
4 ) face the back of these plates towards the flam
5 ) should both be the same distance away from the flame
Record when ball falls first

Question 3

Explaining the results of absorbing IR radiation

Answer 3

Plates absorb infrared radiation given out by bunsen burner
Energy transferred to the thermal energy stores of the candle
Candle wax starts to melt, causing ball to fall.
Quicker the ball falls from the plate the better it is sbsorbing infrared radiation

Question 4

How does the amount of infrared depend on the surface

Answer 4

How shiny or rough it is and what colour it is

Question 5

Wht can you investigate with a Leslie Cube

Answer 5

Emission

Question 6

Practical ivestigating IR radiation with leslie cube

Answer 6

1) Place an empty Leslie Cube on heat proof mat
2) Draw a square around the cube that is 10 cm from all faces of cube
3) fill Leslie Cube with boiling water and wait for the dube to warm up.
4 ) Use the square you’ve drawn to hold an infrared detector 10 cm away from one of the cube’s vertical faces.
5 ) Record the amount of IR radiation it detects
Repeat steps 4 and 5 for each of the four faces.
7( face with the highest reading is giving off the most radiation
8 ) You ahould find the black face is radiating more than thr white surface
Matt surfaces should gove off more than shiny ones

Question 7

What can you investigate with the practical of investigating springs

Answer 7

The link between force and exension

Question 8

Practical of Investigating Springs

Answer 8

1 ) Set up apparatus - foxed ruler, clamp , spring , extra masses,
2 ) measure the mass of each mass
3 ) calculate the weight using W
4 ) measure original length of the speing
5 ) add a mass to the speing and allow it to come to rest
6 ) record the force and measure the new length of spring
7 ) find the extension
8 ) repeat steps 5 to 7 until you’ ve added all the masses
9 ) plot a corce extension graph of results