Unit 9 Space travel

Topic

Balloon rocket

Curriculum Link

9.4 A space journey: action and reaction

Estimated Lesson Time

80 minutes

Introduction

This activity is mainly about a simple and fun competition on balloon rocket. Students are asked to make a balloon rocket which can travel the longest distance. Besides identifying the factors affecting travel distance, students are also guided to know the existence of Action and Reaction pair. It is worth to remind students that action and reaction forces are acting on different objects and will not cancel each other. In order to make this concept visible, students will also learn how to draw force diagram.

Key Question

What are the factors affecting travel distance of balloon rocket?

Learning Objectives

In this activity, the students should be able to

  1. understand the working principle of launching rocket as an action and reaction pair;
  2. explore the factors to be considered in making balloon rocket;
  3. measure and record travel distances of balloon rocket (SP1);
  4. design and make balloon rocket for competition (SP3) ;
  5. use force diagram to explain the principle of launching rocket (SP6) .

Teaching Plan

Task (Time) Brief Description Materials Objectives

Engagement
(5 min)

Teacher demonstrates how to launch a balloon rocket along a string.

    

Exploration &
Explanation
(20 min)
  • Ask students to explain why the balloon rocket can move forward. Students usually mention that the balloon rocket is pushed forward by the backward- moving air. Thus, teacher can explain the working principle of launching rocket in terms of ‘action and reaction pair’.
  • Teacher introduces force diagram to help students to visualize the concept of ‘action and reaction pair’.
 (1) & (5)

Elaboration
(10 min)

Ask students to draw force diagram to explain other similar examples with ‘action and reaction pair’.

 (1) & (5)

Exploration &
Elaboration
(20 min)
  • Divide students into groups for balloon rocket competition. In designing balloon rockets, students are asked to discuss the possible factors affecting travel distances of the rockets.
  • In preparing the competition, students are required to measure and record the distances travelled by the balloon rocket in each trial. Teacher monitors how students consider factors affecting the travel distances.
 (2), (3) & (4)

Elaboration &
Explanation
(15 min)

Competition : Invite each group to launch their balloon rockets and explain their designs. Students are required to record the travel distances and make remarks on any characteristics for further analysis.

 (3)

Explanation
(10 min)

Based on the data recorded, students discussed the factors affecting the travel distances when launching the balloon rocket.

 (2)

*Apparatus and materials required: