REFSTUDY GUIDE: Big IdeasUse to answer form questions
1.Energy Conversion: Electric motors convert electrical energy into mechanical energy (motion). Inside a motor, current flows through a coil of wire sitting in a magnetic field. The interaction between the electromagnet and the permanent magnet creates a torque (twisting force) that spins the coil. Efficiency measures how much input energy becomes useful work versus lost as heat — no motor reaches 100%.
2.Mechanical Advantage: Mechanical advantage (MA) is the factor by which a machine multiplies force: MA = output force ÷ input force. Gears and pulleys trade force for distance — a gear ratio of 3:1 triples your force but you must turn the input gear three times as far. This trade-off is fundamental: you can never get more total work out than you put in, but you can choose whether to apply less force over more distance or more force over less distance.
3.Efficiency & Gear Trains: A tiny electric motor can lift a car because it is paired with a high-mechanical-advantage gear train. The motor spins fast with low torque, and the gears convert that into slow rotation with very high torque. This is why car jacks, electric drills, and bike gears all use gear reduction — the motor does the spinning, the gears do the multiplying.
DRAWKEY TERMSGoogle each → Images tab → sketch what you see
energy
Capacity to do work; can be transferred but not created or destroyed
Torque
Rotational force — the twisting power of a motor (measured in Newton-meters)
Mechanical Advantage
Factor by which a machine multiplies force (MA = Output Force / Input Force)
Gear Ratio
Ratio of teeth on driven gear to driving gear; determines speed/torque trade-off
OTHER VOCAB: work · efficiency · pulley system · motor · force · distance
WRITEFOCUS QUESTIONYour initial thinking
A car jack motor is smaller than your fist and runs on a 12V car battery drawing just 15 amps — only 180 watts of power. Yet it can lift a 1,500 kg car (14,700 N) off the ground. The motor itself produces barely enough torque to turn a pencil — so how does it generate enough force to raise 1,500 kg against gravity?
How can a tiny electric motor lift a car?
I think...
WRITEAFTER HOOK FORMReflect before continuing
I learned that...
Station 1 — Motor Efficiency Investigation
I observed that...
This shows that...
The key concept is...
CHECKDAY 1 CHECK-INBefore you leave
Q1:Based on today's investigation of electric motors & mechanical
advantage, explain one key finding using evidence from your data.
Connect your answer to this week's focus question: How can a tiny
electric motor lift a car?
Confidence:
Electric Motors & Mechanical Advantage (Day 2)
Name: Period:
Station 2 — Mechanical Advantage Analysis
The data shows...
This connects to what we learned because...
I can conclude that...
Station 3 — Design a Lifting System
The main idea is...
This connects to what we learned because...
I can apply this by...
DRAWCONCEPT MODELShow your understanding visually
Draw a model that shows the main concept. Include labels and arrows
to explain relationships.
Labels included
Relationships shown
Key terms used
CHECKTEST YOUR THINKINGRate each: FALSE ← 1–2–3–4–5 → TRUE
1. Electricity is 'used up' in devices.
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2. Electricity and magnetism are completely separate phenomena.
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3. Magnets have unlimited strength/never wear out.
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4. A motor that runs out of battery has consumed all the electrical energy — none of it exists anymore.
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5. The magnetic field inside a motor has nothing to do with the electric current flowing through its coils.
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Pick any TWO statements — especially any you rated 2, 3, or 4. Justify your rating with evidence:
Statement #___ — I rated it ___ because:
Statement #___ — I rated it ___ because:
THINKSCIENTIST CIRCLE DEBRIEFReflect after class discussion