• State Newton’s First, Second, and Third Laws of Motion
• Apply each law to solve conceptual and calculation-based problems
• Distinguish between situations governed by each law
• Connect Newton’s laws to real-world phenomena

• Use scientific vocabulary related to Newton’s laws accurately
• Describe forces and motion using proper terms in explanations and diagrams
• Interpret and construct explanations for motion scenarios

Practice with these interactive flashcards to master Newton’s Laws terminology:

Inertia: The tendency of an object to resist a change in its state of motion.

Force: A push or pull that can cause an object to accelerate.

Resultant force: The single force that has the same effect as all the forces acting on a body.

Newton’s Laws describe how forces affect the motionдвижение/қозғалыс of objects.

First Law (Law of Inertia):

“An object remains at rest or in uniform motion in a straight line unless acted upon by a resultant external force.”

Second Law:

“The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.”
Mathematically: F = ma

Third Law:

“Whenever one body exerts a force on a second body, the second body exerts an equal and opposite force on the first.”

Practice Questions

1. (Easy) State Newton’s Third Law and give an example.
Answer
For every action, there is an equal and opposite reaction. Example: When you push on a wall, the wall pushes back on you with equal force.
2. (Medium) Calculate the acceleration of a 5 kg object when a 20 N force acts on it.
Answer
a = F/m = 20 N / 5 kg = 4 m/s²
3. (Medium) Explain how seatbelts demonstrate Newton’s First Law.
Answer
In a sudden stop, your body tends to keep moving (inertia). The seatbelt provides the unbalanced force to stop you.
4. (Hard) Two ice skaters push off from each other on frictionless ice. Skater A has mass 60 kg, Skater B has mass 40 kg. If A moves at 3 m/s, what is B’s velocity?
Answer
By conservation of momentum: 60×3 + 40×v = 0 ⇒ v = -4.5 m/s (opposite direction)

1. State Newton’s Second Law in words and as a formula.
2. What is inertia?
3. Provide an example for each of Newton’s three laws.
4. What does a resultant force of zero mean for an object?
5. Define action and reaction forces.

• Newton’s Laws Song
• Real-life Examples of Newton’s Laws
• Forces and Motion in Sports

Example 1

Problem: A box of mass 10 kg is pulled with a force of 30 N. What is its acceleration?

Example 2

Problem: Why does a rocket accelerate upward?

Try the simulation:

1. Change the force applied to an object. What happens to its motion?
2. Set the net force to zero. Describe the object’s motion.
3. Try changing masses and compare accelerations for the same force.

• Work in pairs to match real-life scenarios to Newton’s laws.
• Discuss which law applies to each scenario and explain why.

1. A force of 50 N is applied to a 4 kg object. What is its acceleration?
2. Describe the motion of a car after the engine is turned off while moving on a frictionless surface.
3. Two skaters push off against each other. How do their movements demonstrate Newton’s Third Law?
4. A box sits on a table. Identify all the action-reaction pairs acting on the box.
5. Explain why seatbelts are important in terms of inertia and Newton’s laws.

• Save My Exams — Newton’s Laws
• Physics & Maths Tutor — Mechanics
• PhET Simulation: Forces and Motion
• BBC Bitesize – Newton’s Laws

• Which of Newton’s laws do you find easiest to apply? Why?
• What real-life scenarios can you now analyze using Newton’s laws?
• How do you recognize when each law is relevant in a problem?
• What questions do you still have about forces and motion?

Rate your confidence (1-5) for each learning objective and review resources for any rated 3 or below.