Year 7 Science · Unit 3 · Lesson 12

Electrostatic and Gravitational Forces

Challenge Worksheet

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Date

Class

Learning Goals

Apply your understanding of charge and mass to a hypothetical scenario.
Predict and reason about the consequences of changing how a force behaves.
Evaluate the deeper differences between the electrostatic and gravitational forces.

Go Deeper

What if…?

Scenario

Imagine that overnight the gravitational force changed its nature: it could now repel as well as attract, just like the electrostatic force. From now on, very large masses push away from each other, while small masses still attract. Earth's mass, the planets' masses, and all their speeds stay exactly the same. Only this new "repel" ability has been added to gravity.

Using what you know about gravity, mass, distance, and how the Sun's gravity holds the planets in orbit, predict and explain what would change about the Solar System and everyday life on Earth. Use scientific terms (gravitational force, mass, attract, repel, non-contact force, orbit) in your answer. Consider at least two different consequences.

Challenge 4 marks

Show What You Know

1. Both the electrostatic force and the gravitational force get weaker as objects move further apart, and both act across a gap. Despite these similarities, why can the electrostatic force do something gravity can never do? Explain using the idea of positive and negative charge.

Challenge 3 marks

2. A charged balloon is held near a wall and sticks to it, but after a few minutes it slowly slides down and falls to the floor. Explain what is happening using both the electrostatic force and the gravitational force, and describe how the balance between them changes over time.

Challenge 4 marks

Wrap Up

In one sentence, what was the main idea of this lesson?