Digging - The PjProblemStrings Sequences.
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Digging - The PjProblemStrings Sequences

One of the ways humans derive benefits from the earth is to dig it. They dig earth to sow; they dig it to build; they dig it to mine; they dig it to hide valuables and they dig it to bury their loved ones.
(a) The illustrated bulldozer is engaged in simple digging. Highlight its digging.
(b) Indicate the PjProblem Strings for the highlights. Thus establish the PjProblemStrings Sequences for the digging.
Other livings things are also diggers: some rodents dig to hibernate (e.g. the groundhog); bears dig to find food; dogs dig when hot in search of cool space; squirrels dig to hide their food and trees dig in search of water and nutrients.
(c) How does the digging of a tree differ from the digging of the illustrated bulldozer.
(d) Do you agree that walking on sand is digging? If you do, differentiate the digging that results from walking on sand from the digging of the illustrated bulldozer.
(e) Suggest two prerequisites one would need inorder to formulate a mathematical model for the digging of the bulldozer.
(f) Explain the correctness or incorrectness of the following assertion: every movement on the ground is digging.

The strings: all PjProblems at play.

The math: S7P3A32 (force - push) and S7P3A31 (force -pull) are the PjProblems of interest.

(a) : operator of bulldozer positions it some distance from the perimeter of the earth space to be dug.
- Bulldozer's blade is pushed into space to be dug
- Bulldozer's blade scoops some earth
- Bulldozer's blade containing scooped earth is raised.
- Bulldozer moves scooped earth to dump-space.
- Bulldozer's blade returns to space being dug.
This completes the digging cycle which is repeated until the digging is completed. The position of the bulldozer around the space being dug may vary.

(b) : - Operator in bulldozer and bulldozer's position - S7P1A17 (containership - location)
- Earth space being dug - S7P2A21 (identity - physical)
- Bulldozer's blade pushes into earth - S7P3A32 (force - push)
- Bulldozer's blade scoops some earth - S7P3A31 (force - pull)
- Bulldozer raises scooped earth - S7P4A41 (motion - linear)
- Bulldozer moves scooped earth to dump-space - S7P4A42 (motion - curvilinear)
- Bulldozer's blade returns to space being dug - S7P4A42 then S7P4A41
Thus, the digging PjProblemStrings Sequences are : S7P1A17S7P2A21S7P3A32S7P3A31S7P4A41S7P4A42S7P4A42S7P4A41
Some PjProblem Strings not directly influencing the digging are implied. For example, the equlibrium of the operator and the bulldozer, the grouping/interaction and equilibrium of the earth dumped.

(c): the roots of trees are the diggers. They only push through earth in their search for water and nutrients. They do not pull earth.

(d)Yes. It is a push-digging.

(e)There are several variables in the digging scenario presented.
So, first prerequisute: the variable or variables of interest must be identified.
Second prerequisite: assumptions must be made to reduce the inherent complexities of the model. The assumptions made will depend on the variables of interest.

(f)The assertion every movement on the ground is digging is correct because all movements on the ground exert push-forces. The extent to which the digging impressions are perceived is dependent on the push-force and the compactness of the ground.
In general, all exertions of forces on matter are diggings. The visibility or invisibility of the digging impressions is dependent on the severity of the force and the strength of the material relative to the force.

Blessed are they that have not seen, and yet have believed. John 20:29