Science · Year 5 · Forces in Action · Summer Term

Introduction to Forces

Defining what a force is and identifying different types of forces acting on objects.

• National Curriculum Attainment Targets
• NC-KS2-Science-Y5-Forces-1

About This Topic

Gravity and Resistance explores the invisible forces that govern how objects move on Earth. Students investigate gravity as a pull toward the center of the Earth and learn how air and water resistance act as opposing forces. This topic is a key part of the KS2 Forces curriculum, requiring students to explain that unsupported objects fall towards the Earth because of the force of gravity and to identify the effects of air resistance, water resistance, and friction.

Understanding these forces is essential for explaining everything from why we stay on the ground to how parachutes and boats work. It introduces the concept of 'balanced' and 'unbalanced' forces. This topic comes alive when students can conduct experiments, such as dropping objects of different shapes or designing streamlined vehicles, to see the direct impact of resistance in action.

Key Questions

1. Explain what a force is and how it can change an object's motion.
2. Identify different types of forces acting on everyday objects.
3. Predict how applying a force will affect an object's movement.

Learning Objectives

• Define the term 'force' and explain its effect on an object's motion, including starting, stopping, or changing direction.
• Identify at least three different types of forces (e.g., gravity, friction, air resistance, push, pull) acting on everyday objects.
• Predict the outcome of applying a specific force to an object, such as a ball rolling down a ramp or a book sliding across a desk.
• Compare the effects of different forces, such as friction versus no friction, on an object's movement.

Before You Start

Properties of Materials

Why: Students need to understand the physical properties of objects, such as their shape and surface texture, which influence how forces like friction and air resistance affect them.

Movement and Speed

Why: A basic understanding of how objects move and the concept of speed is necessary to explain how forces can change an object's motion.

Key Vocabulary

Force	A push or a pull that can cause an object to move, stop moving, or change direction.
Gravity	A force that pulls objects towards each other, especially towards the center of the Earth, causing things to fall.
Friction	A force that opposes motion when two surfaces rub against each other, slowing things down.
Air Resistance	A type of friction that occurs when an object moves through the air, slowing it down.
Push	A force that moves something away from you.
Pull	A force that moves something towards you.

Watch Out for These Misconceptions

Common Misconception

Heavier objects fall faster than lighter ones.

What to Teach Instead

This is a very common belief. By dropping a heavy ball and a light ball of the same size simultaneously, students can see they hit the ground at the same time. This surfaces the idea that gravity acts equally on all mass, and it's actually air resistance that slows some things down.

Common Misconception

There is no gravity in space.

What to Teach Instead

Students often think astronauts float because there is 'zero gravity.' Peer discussion about how gravity keeps the Moon in orbit around Earth helps them realize gravity is everywhere in space, but astronauts feel weightless because they are in a constant state of freefall.

Active Learning Ideas

Inquiry Circle: The Parachute Challenge

In small groups, students design and build parachutes using different materials and surface areas. They drop them from a height and time the fall, discussing how the air resistance (upward force) opposes gravity (downward force) to slow the descent.

60 min·Small Groups

Simulation Game: Streamlining in Water

Students shape pieces of modeling clay into different forms (e.g., a ball, a flat disc, a teardrop) and time how long they take to sink to the bottom of a tall water container. They use their findings to explain how shape affects water resistance and why fish and boats are streamlined.

45 min·Small Groups

Think-Pair-Share: Gravity on the Moon

Students watch a video of astronauts jumping on the Moon. They think about why the jumps are so much higher than on Earth, pair up to discuss the relationship between a planet's mass and its gravitational pull, and then share their conclusions with the class.

25 min·Pairs

Real-World Connections

• Engineers designing race cars consider air resistance and friction to make vehicles faster and more stable on the track.
• Athletes like sprinters and swimmers use their understanding of forces to improve performance, minimizing air or water resistance while maximizing the force they apply to move forward.
• Toy designers create products like toy cars and balls that demonstrate different forces, allowing children to explore how pushes, pulls, and friction affect movement.

Assessment Ideas

Exit Ticket

Provide students with a picture of a playground scene (e.g., a child on a swing, a ball rolling). Ask them to list three forces they can see or infer in the picture and briefly describe what each force is doing.

Quick Check

Hold up various objects (e.g., a book, a pen, a crumpled piece of paper). Ask students to identify a force they could apply to each object and predict how the object would move. For example, 'What force could you apply to the book, and what would happen?'

Discussion Prompt

Pose the question: 'Imagine you are pushing a heavy box across the floor. What forces are acting on the box? What would happen if you stopped pushing? Explain your reasoning using the vocabulary we learned.'

Frequently Asked Questions

What is gravity?

Gravity is a force of attraction that pulls all objects with mass toward each other. On Earth, gravity pulls everything toward the center of the planet, which is why things fall 'down.' The more mass an object has, the stronger its gravitational pull.

How does air resistance work?

Air resistance is a type of friction that occurs between a moving object and the air particles around it. As an object moves, it has to push air out of the way. This creates a force that acts in the opposite direction to the object's motion, slowing it down.

How can active learning help students understand gravity and resistance?

Forces are invisible, which makes them hard to understand through reading alone. Active learning, like the parachute challenge, makes these forces 'visible' through their effects. When students feel the 'tug' of a parachute or see a streamlined shape slice through water, they are building a physical intuition for how forces interact in the real world.

What does 'streamlined' mean?

An object is streamlined if it has a shape that allows it to move through air or water with as little resistance as possible. Streamlined shapes are usually pointed or rounded at the front and smooth along the sides, like a shark or a racing car, to help them move faster and more efficiently.