Answer 2_5_11
Here are the results of an experiment:
|
Joulemeter
reading at the start |
31225
J |
|
Joulemeter
reading at the end |
43120
J |
|
Temperature at the start |
23
oC |
|
Temperature at the end. |
58
oC |
|
Mass of the material |
1.25
kg |
|
Time taken |
250
s |
(a) Which piece of data is irrelevant?
The time taken is only relevant if we are interested in power.
(b) What is the specific heat capacity of the material?
Formula first: Q = mcDq
Temperature change = 58 - 23 = 35 o C (= 35 K)
Energy = 43120 - 31225 = 11895 J
11895 J = 1.25 kg x Specific heat x 35 K
Specific heat = 11895 = 272 J kg-1 K-1
1.25 x 35