Assessment Task
Practical Investigation
Instructions:
- It is very important that you read these instructions.
- The hardcopy of the Assignment report, with the Assignment cover sheet, should be submitted to the Assignment box on the same day.
- This is strictly an individual assignment.
- Question 1 requires selecting reference points from the graph. Each student will choose different reference points to other students.
- For Questions 4-8 each student will be given particular values to use.
- Take note of the criteria for the marking of the assessment tasks.
These criteria include:
Accuracy of Calculations - being aware of accuracy required and applying of problem solving is shown and methods and accurately and consistently.
Problem solving - evidence assumptions are clearly explained
Use of Technology - this needs to be used appropriately and evidence clearly given.
Quality of Analysis and Conclusions - results of calculations are to be analysed and conclusions drawn.
Presentation of the Report - the report should be presented clearly as for a minor project: Introduction/ Conclusions/ Headings/subheadings/ diagrams/ graphs/ tables/ correct labelling etc
Practical Investigation Part 2
The channel has a cross-section in a form of a parabola. The maximum width of the channel at the existing ground level as shown in Figure 2 is W metres.
1. Determine the depth of the channel below the existing ground level if the minimum cross section area of the channel (below ground level) is A m2 and hence determine the channel x-section profile equation.
2. The excavated earth is used for the embankments alongside the channel. The cross section of the embankments as shown in Figure 2 is in the form of a symmetrical trapezium. The sides of the trapezium are tangential to the excavated channel at the ground level. The width of the top of the trapezium is t metres. Determine the height of the trapezium.
3. The maximum safe flow capacity of the channel is when the channel is full up to 0.7 of the full height of the channel. Determine the maximum safe area for the safe flow.
4. To reduce the scouring of the channel and the water seepage, it is suggested to use a lining material to the full height of the channel. If the lining material costs around $40.00 per square metre, determine the cost of lining per metre length of the channel.
5. If the cost of excavation is $12 per cubic metre, the cost of constructing the embankment is $15.00 per cubic metre and the cost of the lining material is $40.00 per square metre, suggest an alternative profile for the channel x-section with less cost. The only constraints are the overall width of the channel should not be more thanmetres and the minimum cross sectional area for the water flow is A SQM.