Newton's Laws of Motion

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CognitoNewton's laws of motion

CognitoTerminal velocity

Key facts & equations

Newton's three laws — fill in the table

Law	Statement
1st Law
2nd Law
3rd Law
3rd Law pairs
Example

Weight and mass — fill in the table

Term	Definition
Weight
g on Earth
Weight vs mass
On the Moon
Normal force

F = ma calculations

F = ma → a = F/m → m = F/a.
Resultant force: the vector sum of all forces. Use free body diagrams.
If resultant force = 0: constant velocity (or at rest). If F ≠ 0: acceleration.
Example: car mass 1000 kg, engine force 3000 N, friction 1000 N.
Resultant F = 3000 - 1000 = 2000 N. a = F/m = 2000/1000 = 2 m/s².

Terminal velocity — fill in the table

Stage	What happens
Falling through fluid
Initially
At terminal velocity
Skydiver
On opening parachute

Exam questions — 4 questions · 10 marks · AQA 8463 style

1 markNewton 2nd lawAQA 8463 style

A resultant force of 800 N acts on a 200 kg object. What is the acceleration?

A 160,000 m/s²

B 0.25 m/s²

C 4 m/s²

D 600 m/s²

3 marksForce calculationAQA 8463 P1 style 🔢 Calculator

A 1500 kg car accelerates at 3 m/s². There is a friction force of 500 N. Calculate the engine driving force. (3 marks)

Hint: Step 1: F_resultant = ma. Step 2: F_resultant = F_drive - F_friction. Rearrange to find F_drive.

+30 XP

1 markTerminal velocityAQA 8463 style

A skydiver reaches terminal velocity. Which statement is correct?

A The skydiver is accelerating upwards

B Weight is greater than air resistance

C Air resistance equals weight — zero resultant force — constant velocity

D Air resistance is zero

4 marksNewton 3rd law pairsAQA 8463 style

A book rests on a table. (a) State the weight of the book. (b) Identify the Newton's 3rd law pair to the weight of the book. (c) Is the normal force from the table a Newton's 3rd law pair to the book's weight? Explain. (3 marks)

Hint: 3rd law pairs: same type, same magnitude, opposite direction, DIFFERENT objects. Weight pairs with the book's pull on Earth — not with the normal force.

+40 XP

Quick recall flashcards

Newton's Laws of Motion

Newton's three laws — fill in the table

Weight and mass — fill in the table

F = ma calculations

Terminal velocity — fill in the table

Module complete! 🎉