Forces in Action · Summer Term

Effects of Forces on Motion and Shape

Investigating how forces can change an object's speed, direction, or shape.

About This Topic

Gravity and space explore the forces that shape our solar system and the universe. Students learn about the gravitational pull of the Sun and planets, and how this pull keeps celestial bodies in orbit. They also investigate the difference between mass and weight and the causes of the changing phases of the moon.

This topic aligns with the National Curriculum attainment targets for space physics and forces. It provides a grand perspective on our place in the universe and the fundamental laws that govern it. Understanding gravity and space is essential for students to appreciate the scale and complexity of the cosmos. This topic particularly benefits from hands-on, student-centered approaches where students can physically model the patterns of planetary motion.

Active Learning Ideas

Simulation Game: The Human Solar System

Students take on the roles of the Sun, planets, and moons. They must move in their respective orbits at relative speeds, demonstrating how gravity keeps the system together and how the moon's phases occur.

⏱ 30 min·Whole Class

Generate mission

Inquiry Circle: Weight on Other Worlds

Groups use a set of 'planetary scales' (or calculated data) to determine their weight on different planets. They must explain why their mass remains the same while their weight changes based on the planet's gravity.

⏱ 40 min·Small Groups

Generate mission

Think-Pair-Share: The Moon's Changing Face

Students are shown a diagram of the Earth-Moon-Sun system. They work in pairs to explain why we see different amounts of the moon's lit side from Earth, then share their explanations with the class.

⏱ 20 min·Pairs

Generate mission

Watch Out for These Misconceptions

Common Misconception

There is no gravity in space.

What to Teach Instead

Explain that gravity is everywhere in space and is what keeps planets in orbit. The 'weightlessness' felt by astronauts is actually due to them being in constant free-fall. Using a simulation of orbital motion can help clarify this.

Common Misconception

The phases of the moon are caused by the Earth's shadow.

What to Teach Instead

Clarify that the phases are caused by our changing view of the moon's sunlit half. A hands-on activity with a lamp and a ball (representing the Sun and Moon) is the best way to correct this common error.

Frequently Asked Questions

What is the difference between mass and weight?

Mass is the amount of matter in an object and is measured in kilograms (kg). Weight is the force of gravity acting on that mass and is measured in Newtons (N). While mass stays the same everywhere, weight changes depending on the strength of gravity.

How can active learning help students understand gravity?

Active learning, such as creating a 'Human Solar System' or using data to calculate weight on other planets, makes the vast scales of space more relatable. By physically acting out orbits or comparing their own 'weight' across the solar system, students develop a more intuitive understanding of how gravity functions as a universal force.

What keeps the planets in orbit around the Sun?

The Sun's massive gravitational pull acts as a centripetal force, constantly pulling the planets towards it. This pull, combined with the planets' forward motion, results in a curved path or orbit.

Why do we only ever see one side of the moon?

The moon rotates on its axis at the same rate that it orbits the Earth. This is called synchronous rotation, and it means that the same side of the moon is always facing our planet.

Browse curriculum by country

• Americas
• US
• CA
• MX
• CL
• CO
• BR

• Europe
• UK
• IE
• FR
• DE
• ES
• IT
• NL
• PT
• SE

• Asia & Pacific
• IN
• SG
• AU