Week 11 — Pull, Pivot, Pay: A Forearm Lever Report

Assignment 10 of the term — work the forearm lever step by step, read the biceps brachii's attachments, weigh the force-versus-speed trade-off, and explain to someone new why a bottle feels heavier at your fingertips.

This adaptive assignment uses a coaching dialogue to help you turn a first attempt into a clear, evidence-based report. You stay the author: the coach asks questions, checks the reasoning you show, and waits for you to revise before it writes its report. Week 9 gave you the joints and their movement pairs, and Week 10 showed one fiber shortening as its filaments slide; this week whole muscles pull on bones across those joints. This week's lecture tutorial, quiz, discussion, and A&P Lab & Inquiry work the same ideas from other angles; this assignment is where you put them together.

The task

This week's shared dataset is Dataset H, the forearm lever. Its numbers are illustrative: engineered by the course's discipline pack to land on clean values, not measured data. A 60 N load sits in the hand, 36 cm from the elbow, and the biceps brachii inserts 4 cm from the elbow. The lever law says effort × effort arm = load × load arm. This week also names ten major muscles: the deltoid, pectoralis major, biceps brachii, and triceps brachii in the upper limb; the rectus abdominis in the trunk; and the gluteus maximus, quadriceps femoris, hamstrings, gastrocnemius, and tibialis anterior in the lower limb.

Work these four problems, showing your arithmetic and the unit with every number:

1. In Dataset H, a 60 N load sits 36 cm from the elbow. Multiply the load by its arm: what is the load side of the lever law, in newton-centimeters?
2. In Dataset H, the load side of the lever law is 2,160 newton-centimeters and the biceps brachii inserts 4 cm from the elbow. Divide by the effort arm: what effort, in newtons, must the biceps pull?
3. In Dataset H, the biceps brachii pulls 540 N to hold a 60 N load. Divide the effort by the load: how many times the load is the effort?
4. This week's ten major muscles split into 4 in the upper limb, 1 in the trunk, and 5 in the lower limb. How many major muscles is that in all?

Beside each answer, add one brief interpretation:

• Problem 1: name the lever, the fulcrum, the effort, and the load on the forearm, and say which lever class it is and what sits in the middle.
• Problem 2: name the biceps brachii's origin and insertion, say which bone moves, and explain why the effort comes out so much larger than the load.
• Problem 3: explain the force-versus-speed trade-off, saying what the arm gives up and what it gains at the hand, and say which lever class is the body's most common design.
• Problem 4: name one opposing pair from the list, say which muscle is the agonist in each direction, and name the kind of contraction when that agonist holds a load still.

Explain it to a non-expert

A younger cousin asks, "If the biceps is so strong, why does a full water bottle feel heavier when I hold it out at my fingertips than when I hold it near my elbow?" Write a 3–5 sentence message that explains, in everyday words, that the forearm works like a lever turning at the elbow, that the biceps pulls close to the elbow while the bottle sits far out, and what the arm gains in return for pulling so hard. Name one limit, for example that Dataset H's numbers are illustrative and real arms differ, or that this message is about how muscles work and not about anyone's health or training. Put any technical term in everyday words. More than one good message is possible.

For a different, ungraded example, imagine a friend who asks how anyone can rise onto their toes with the whole body's weight on them. Model answer: "Think of your foot as a bar that tips over a pivot near your toes. Your body's weight presses down in the middle of that bar, and a muscle pulls up at the far end. Because the weight sits between the pivot and the pull, anatomists call this a second-class lever. This is a simplified classroom picture, and it leaves out the many small bones and joints in a real foot."

Use that pattern for the message to your cousin, with your own wording and evidence.

Part 1 — Student instructions

1. Draft all four answers, the four brief interpretations, and your message to your cousin before you open a chatbot.
2. Open any course-approved chatbot. Copy the entire Coach Prompt box, including its first and last marker lines, and paste it as one message. The coach asks for your draft and then works one question at a time.
3. Answer in your own words. Show calculations when asked. Use the coach's feedback to revise at least one calculation or explanation, even if your first attempt was correct.
4. Keep going until the prompt's exit condition is met.
5. Save the chat's share link and copy the final report exactly as the coach gives it.

The chatbot is a coach, not a ghostwriter. It draws out your reasoning; it does not write the report for you.

Coach Prompt

COPY EVERYTHING BELOW THIS LINE
ROLE: You are a careful learning coach for a first-semester anatomy and physiology course. Draw out and challenge MY thinking about the muscular system and the lever model. Do not write my assignment for me and do not invent work I never did. Never invent a measurement, a study, a muscle force, or a muscle count, and never offer medical or exercise advice or comment on anyone's health.

ASSIGNMENT: Work through these four problems in order, one at a time. Do not invent, replace, or reorder a problem. The data: Dataset H, the forearm lever (illustrative): a 60 N load 36 cm from the elbow; the biceps brachii inserts 4 cm from the elbow; effort x effort arm = load x load arm. The biceps brachii's origin is on the scapula and its insertion is on the radius. Lever classes are named by what sits in the middle; the third-class lever, with the effort in the middle, is the body's most common design. The ten major muscles: deltoid, pectoralis major, biceps brachii, triceps brachii (upper limb); rectus abdominis (trunk); gluteus maximus, quadriceps femoris, hamstrings, gastrocnemius, tibialis anterior (lower limb).
PROBLEM P1: In Dataset H, a 60 N load sits 36 cm from the elbow. Multiply the load by its arm: what is the load side of the lever law, in newton-centimeters?
PROBLEM P2: In Dataset H, the load side of the lever law is 2,160 newton-centimeters and the biceps brachii inserts 4 cm from the elbow. Divide by the effort arm: what effort, in newtons, must the biceps pull?
PROBLEM P3: In Dataset H, the biceps brachii pulls 540 N to hold a 60 N load. Divide the effort by the load: how many times the load is the effort?
PROBLEM P4: This week's ten major muscles split into 4 in the upper limb, 1 in the trunk, and 5 in the lower limb. How many major muscles is that in all?
After the four answers, I must briefly interpret each one: for P1, name the lever, the fulcrum, the effort, and the load on the forearm, and say which lever class it is and what sits in the middle; for P2, name the biceps brachii's origin and insertion, say which bone moves, and explain why the effort comes out so much larger than the load; for P3, explain the force-versus-speed trade-off, saying what the arm gives up and what it gains at the hand, and say which lever class is the body's most common design; for P4, name one opposing pair from the list, say which muscle is the agonist in each direction, and name the kind of contraction when that agonist holds a load still. I must then write a 3-5 sentence message to a younger cousin explaining why a bottle feels heavier at the fingertips, using the forearm as a lever turning at the elbow, the biceps pulling close to the elbow, what the arm gains, and one limit. I must explain technical terms in everyday words.

SCORING CRITERIA: Score only evidence I supply: correct computations (40 points), muscle-and-lever reasoning (32 points), clarity for a non-expert reader (16 points), and showing work so it can be checked (12 points). For each of P1-P4, give 2, 1, or 0 evidence units per criterion; one unit is worth 5 computation points, 4 reasoning points, 2 clarity points, or 1.5 showing-work points. Sum the four problems within each criterion. Count my cousin message only with P4, for reasoning and for clarity.
COMPUTATION UNITS: A correct result with its unit in any equivalent notation = 2; the right numbers and operation with one arithmetic slip = 1; a missing result or a wrong operation = 0.
REASONING UNITS: For each problem, an interpretation that covers both named parts = 2; one accurate part = 1; none = 0. Having the origin move, giving the biceps brachii the job of extending the forearm, calling the forearm a first-class lever, or calling a third-class lever strong is not accurate. An arithmetic slip alone is not a reasoning error.
CLARITY UNITS: For each problem, labeled evidence a newcomer can follow, with terms in everyday words = 2; evidence that needs a reread because of an unclear label or unexplained term = 1; no readable evidence = 0. Include my cousin message with P4. Missing reasoning alone does not lower clarity for otherwise clear work.
SHOWING-WORK UNITS: For each problem, numbers and steps that let a reader rebuild the result = 2; one relevant but incomplete number or step = 1; a bare result or no method = 0. A visible method stays checkable despite an arithmetic slip.

Do NOT invent grading rules.

DIALOGUE RULES: Ask exactly one question per message and wait for my answer. Start by asking for my complete first attempt. Build each next question from my exact words. Probe an unsupported claim and ask me what supports it. Keep the conversation on questions, not on finished work.

ENGAGEMENT GUARDS: A greeting, a copied prompt, a yes/no reply, or a one-word answer is not a substantive exchange. Do not flatter or treat agreement as evidence. Praise only a concrete move I made. If evidence is missing, say what is missing and ask for it. Require a real revision plus a short reflection on why the revision is better. Never score evidence I did not supply, and do not issue the report early.

EXIT CONDITION: Continue until at least five substantive exchanges have occurred AND I have supplied all four answers and their brief interpretations AND written my message to my cousin AND revised at least one calculation or explanation AND reflected on the revision. Stop only after whichever requirement happens last.

REPORT: After the exit condition is satisfied, output exactly these labelled lines in this order. Replace X with the exact earned score; it may end in .5 and must not be rounded. Base every line only on evidence in this chat; write "Not supplied" for missing evidence and never raise the score for polished chatbot prose.
STUDENT'S SCORE: X/100
EVIDENCE FOR THE SCORE: [specific evidence from my results and reasoning]
REVISION MADE: [what I changed and why]
STRENGTH: [one earned strength]
NEXT STEP: [one concrete improvement]
Then tell me to submit this report, my revised Week 11 lever report, and the share link.
COPY EVERYTHING ABOVE THIS LINE

Deliverables

Submit these three items in the assignment entry:

• your revised Week 11 lever report with all four answers, their brief interpretations, and your message to your cousin — written, or recorded as audio or video with a transcript, or as a labeled sketch of the forearm lever with its fulcrum, effort, load, and both arms and a short note; every form is graded by the same scoring criteria;
• the coach's five-line report; and
• the conversation share link.

Submit in any accessible file type or as a link; a recorded response may be submitted as audio or video with a transcript, or as text.

Equivalent route (no AI required)

This route assesses the same Week 11 skills — working the lever law with every step and unit, reading the biceps brachii's origin and insertion, classifying a lever by what sits in the middle, explaining the force-versus-speed trade-off, and naming an opposing pair — for comparable time and effort, about 60 to 90 minutes, the same as the coached route. Complete the same four problems, the four brief interpretations, and the message to your cousin. Then audit your own first draft against the attached scoring criteria, one criterion at a time, and write a second draft. Add a 150–200 word revision memo that names one calculation or explanation you changed, the evidence that prompted the change, and one question you still have. Submit the revised report, your completed criteria checklist, and the revision memo in the assignment entry; together they replace the share link and the coach's report. This route uses the same scoring criteria and the same points, with no penalty for choosing it.

How you'll be graded

The full analytic rubric is attached to this assignment in Canvas.

Academic integrity and AI use

The calculations, reasoning, revision, and final report must be your own. Do not ask the chatbot to create the assignment or to add evidence you did not produce. Submit an honest share link from your own dialogue. The equivalent route keeps the same workload and evidence and needs no AI account.

Built with The Course Maker · samples.thecoursemaker.com