Newton's Second Law – GCSE Physics

Practice Questions
Downloads

Introduction

  • Newton’s Second Law of Motion states, Non-Zero Resultant Force acts on an object, then it will cause the object to Accelerate.
  • Where Acceleration is,

acceleration formula gcse

Example: Pushing a Shopping Cart:

  • If we push an empty shopping cart with certain force, then it Accelerates quickly.
  • If we push a loaded shopping cart with same force, then it Accelerates slowly.

A comparison of two shopping carts showing how one accelerates quickly and the other slowly, demonstrating Newton's 2nd Law of motion. The left cart is empty and accelerates quickly, while the right cart is full and accelerates slowly.

What is Newton’s 2nd Law of Motion?

  • It states that, Acceleration of an object is directly proportional to the net Force acting on it and inversely proportional to its Mass.
  • Mathematically,

Newton's Second Law equation showing the relationship between acceleration, force, and mass. The formula is displayed as a = F/m or F = ma, where 'a' is acceleration, 'F' is force, and 'm' is mass.

Where,

  • F = Net Force applied
  • m = Mass of an Object
  • a = Acceleration

certified Physics and Maths tutorSolved Example

Problem: If you push a 10 kg box with a 20 N force, what is the Acceleration of the Box?

Solution: 

Step #1: Given

    • F = 20N
    • M = 10kg

Step #2: Using the value:

Newton’s Second Law formula showing acceleration (a) equals force (F) divided by mass (m), a = F/m.

Step #3: Putting the Values:

Example of Newton’s Second Law: acceleration (a) calculated as 20 N of force divided by 10 kg mass, resulting in 2 m/s² acceleration.

Final Answer: 2 m/s2

certified Physics and Maths tutorSolved Example

Problem: A 5 kg box is pushed with a net force of 20 N. What is the acceleration of the box?

Solution: 

Step #1: Given

    • F = 20N
    • M = 5 kg

Step #2: Using the value:

Newton’s Second Law formula showing acceleration (a) equals force (F) divided by mass (m), a = F/m.

Step #3: Putting the Values:

Final Answer: 4 m/s2

certified Physics and Maths tutorSolved Example

Problem: A car with a mass of 1000 kg accelerates at 2 m/s². What is the net force acting on the car?

Solution: 

Step #1: Given

    • A = 20m/s2
    • M = 1000 kg

Step #2: Using the value:

Step #3: Putting the Values:

Final Answer: 2000 N

How Newton’s 2nd Law Works?

  • Newton’s Second Law explains how an object’s motion changes when a force is applied.

Relationship between Force, Mass and Acceleration:

  • Force is directly proportional to Acceleration when Mass is constant.

Newton’s Second Law showing force (F) is directly proportional to acceleration (a), with mass constant.

  • Force is directly proportional to Mass when Acceleration is constant.

Newton’s Second Law showing force (F) is directly proportional to mass (m), with acceleration constant.

  • Acceleration is inversely proportional to Mass when Force is constant.

Newton’s Second Law showing that acceleration (a) is inversely proportional to mass (m) when force is constant.

What is Inertial Mass?

  • Inertial mass is a measure of an object’s Resistance to Acceleration when a Force is applied.
  • If there is more Inertial Mass then, it’s harder to Accelerate.
  • If there is less Inertial Mass then, it’s easy to Accelerate.

Examples:

  • Bicycles are lightweight, stops quickly when brakes are applied while Trucks are Massive, takes much longer to stop even with strong brakes.

Newton’s Second Law demonstrating the relationship between acceleration and mass for two different vehicles.

  • Soccer Ball are low mass, small kick makes it fly fast (large acceleration) while Bowling Ball are high mass, Same kick barely moves it (small acceleration).

A football and a bowling ball demonstrate the effect of force on objects of different mass.

Frequently Asked Questions

Solution:

Newton 2nd Law says that the more force you apply to an object, the faster it will Accelerate. But if the object is heavier, it won’t speed up as quickly with the same force.

Solution:

Use the formula:

Force = Mass × Acceleration (F = m x a).

For example:

if a car has a mass of 1000 kg and accelerates at 2 m/s2, the force is 2000 N.

Solution: 

Mass is how much matter something has. Inertial mass tells us how much an object resists being pushed or sped up. It’s calculated by dividing force by acceleration.

Solution:

Yes. A light bicycle accelerates faster than a heavy car when the same force is applied. This is because the bike has less mass, so it speeds up more.

Solution:

A Newton Second is a unit of Impulse (force x time). It’s not directly part of Newton’s Second Law, but it comes up when studying how momentum changes over time.

Table of Content

Join Tutoring