Science for Grade 4
1 Introduction to Science
1-1 Understanding the Nature of Science
1-2 Importance of Observation and Experimentation
1-3 Scientific Tools and Their Uses
2 Matter and Materials
2-1 Properties of Matter
2-1 1 Solids, Liquids, and Gases
2-1 2 Physical and Chemical Changes
2-2 States of Matter
2-2 1 Characteristics of Solids, Liquids, and Gases
2-2 2 Changes of State (Melting, Freezing, Boiling, Condensation)
2-3 Mixtures and Solutions
2-3 1 Types of Mixtures (Homogeneous and Heterogeneous)
2-3 2 Solubility and Factors Affecting Solubility
3 Force and Motion
3-1 Understanding Force
3-1 1 Types of Forces (Push, Pull, Friction, Gravity)
3-1 2 Effects of Force on Objects
3-2 Motion and Speed
3-2 1 Types of Motion (Linear, Circular, Oscillatory)
3-2 2 Measuring Speed and Distance
3-3 Balanced and Unbalanced Forces
3-3 1 Concept of Equilibrium
3-3 2 Newton's First Law of Motion
4 Energy
4-1 Forms of Energy
4-1 1 Mechanical, Thermal, Light, Sound, Electrical, and Chemical Energy
4-1 2 Transformation of Energy
4-2 Sources of Energy
4-2 1 Renewable and Non-Renewable Energy Sources
4-2 2 Conservation of Energy
5 Earth and Space
5-1 Earth's Structure
5-1 1 Layers of the Earth (Crust, Mantle, Core)
5-1 2 Earth's Surface Features (Mountains, Valleys, Plains)
5-2 Weather and Climate
5-2 1 Weather Patterns and Instruments
5-2 2 Factors Affecting Climate
5-3 Solar System
5-3 1 Planets and Their Characteristics
5-3 2 Moon and Its Phases
6 Living Organisms and Ecosystems
6-1 Classification of Living Organisms
6-1 1 Kingdoms of Life (Plantae, Animalia, Fungi, Protista, Monera)
6-1 2 Basic Needs of Living Organisms
6-2 Ecosystems
6-2 1 Components of an Ecosystem (Producers, Consumers, Decomposers)
6-2 2 Food Chains and Food Webs
6-3 Adaptations and Habitats
6-3 1 Adaptations for Survival
6-3 2 Types of Habitats (Forests, Deserts, Oceans, Grasslands)
7 Health and Nutrition
7-1 Human Body Systems
7-1 1 Digestive, Respiratory, Circulatory, and Nervous Systems
7-1 2 Functions of Body Systems
7-2 Nutrition and Diet
7-2 1 Nutrients and Their Functions
7-2 2 Balanced Diet and Healthy Eating Habits
7-3 Personal Hygiene
7-3 1 Importance of Cleanliness
7-3 2 Preventing Diseases
8 Environmental Science
8-1 Importance of Biodiversity
8-1 1 Types of Biodiversity (Genetic, Species, Ecosystem)
8-1 2 Threats to Biodiversity
8-2 Pollution and Its Effects
8-2 1 Types of Pollution (Air, Water, Soil)
8-2 2 Ways to Reduce Pollution
8-3 Conservation of Natural Resources
8-3 1 Sustainable Use of Resources
8-3 2 Role of Individuals in Conservation
Understanding Force

Understanding Force

Force is a push or pull that can change the motion of an object. It can make objects speed up, slow down, stop, or change direction. Force is measured in units called Newtons (N). There are different types of forces, but the most common ones are contact forces and non-contact forces.

Contact Forces

Contact forces are forces that act when two objects touch each other. These forces require direct contact between the objects to be applied.

Example: When you push a toy car, you are applying a contact force. The car moves because your hand is in direct contact with it, pushing it forward.

Non-Contact Forces

Non-contact forces are forces that act without the need for objects to touch each other. These forces can affect objects from a distance.

Example: Gravity is a non-contact force. The Earth pulls objects towards its center without touching them. When you drop a ball, it falls to the ground because of gravity, even though the Earth and the ball are not in direct contact.

Balanced and Unbalanced Forces

When forces are balanced, they cancel each other out, and the object does not change its motion. When forces are unbalanced, they do not cancel each other out, and the object's motion changes.

Example: Imagine a book lying on a table. The force of gravity pulls the book down, but the table pushes the book up with an equal force. These forces are balanced, so the book stays still. Now, if you push the book to one side, you create an unbalanced force, and the book moves.

Understanding force helps us explain why objects move the way they do. Whether it's pushing a toy car, dropping a ball, or balancing a book on a table, forces play a crucial role in our everyday lives.