# Earth Sciences Tma 02

TMA 02

Question One:
A i. The mean daily precipitation for the experiment for week one is:
Gauge one (without a funnel):
21 mm ÷ 7 = 3 mm
So my mean daily precipitation for gauge one is to one significant figure:
3 mm ± 0.5 mm
Gauge two (with a funnel):
29 mm ÷ 7 = 4.2 mm
So my mean daily precipitation for gauge two is, to two significant figures:
4.2 mm ± 0.5 mm
ii. The mean daily precipitation for week one and two is:
Gauge one (without a funnel):
Week two daily precipitation:
44 mm ÷ 7 = 6.2 mm ± 0.5 mm (To two significant figures)
So you add week one and week two total mean together:
6.2 mm + 3 mm = 9.2 mm
Then to get the mean daily precipitation for the full two weeks:
9.2 mm ÷ 14 = 0.657142857 mm
So the two week mean is to two significant figures:
0.66 mm ± 0.5 mm
Gauge two (with a funnel)
Week two daily precipitation:
54 mm ÷7=7.7 mm ± 0.5 mm (To two significant figures)
So you add week one and week two total mean together:
4.2 mm + 7.7 mm = 11.9 mm
Then to get the mean daily precipitation for the full two weeks:
11.9 mm ÷ 14 = 0.85 mm
So the two week mean is to two significant figures:
0.85 mm ± 0.5 mm
iii.
Table One: summary of information posted to the online wiki for my tutor group.

Name | Location | Period (dates) | Gauge 1
(no funnel)Two-week
mean and uncertainty
/mm | Gauge 2
(with funnel)Two-week
mean and uncertainty
/mm | Factors important to the results |
Eddard Waelwulf | Hull | 6th to the 19th Oct 2012 | 0.6±0.5 | 0.85±0.5 | Gauges were situated on the roof of my house with no overhanging branches or cover. |

iv. Posting of an entry in the online tutor group forum by myself:
‘… John Calvert my results for week one no funnel are the same as yours. But with a funnel mine are different. Interesting. I wonder why your second results (with funnel) are different from mine…’
B. i. Uncertainties in an experiment are, unfortunately, to be expected. Random uncertainties are caused by varying...