Grade 7: Physics

Here is a comprehensive overview of the Grade 7 Physics content, aligned with the British Columbia (BC) Curriculum.

In BC, Grade 7 Science is organized into four key content areas, with Physics being a major component. The physics unit typically focuses on the foundational concepts of Force and Motion.

BC Grade 7 Science: Physics Unit – Force and Motion

This unit explores the fundamental principles that describe how and why objects move. It answers the questions: “What makes objects start moving, stop moving, or change direction?” and “How can we describe and measure motion?”

Overarching Big Ideas (for the Physics Unit)

• The motion of objects depends on their properties and the forces acting on them.

• Energy can be transformed from one type to another.

Core Components of the Grade 7 Physics Unit

Part A: Describing Motion

• Key Concepts: Position, distance, displacement, speed.

• Learning Goals:

  • Describe the position of an object using a reference point.

  • Differentiate between distance (total path length) and displacement (change in position).

  • Calculate the average speed of an object using the formula: Speed = Distance / Time.

  • Interpret and create distance-time graphs to represent and analyze motion.

Part B: Introduction to Forces

• Key Concepts: What is a force? Contact vs. non-contact forces, measuring force.

• Learning Goals:

  • Define a force as a push or a pull.

  • Identify forces as either contact forces (e.g., friction, applied force, tension) or non-contact forces (e.g., gravity, magnetism, static electricity).

  • Understand that force is measured in Newtons (N).

Part C: Newton’s Laws of Motion

• Key Concepts: Inertia, relationship between force and acceleration, action-reaction pairs.

• Learning Goals:

  • Newton’s First Law (Law of Inertia): Explain that an object at rest will stay at rest, and an object in motion will stay in motion at a constant speed and in a straight line, unless acted upon by an unbalanced force.

  • Newton’s Second Law: Describe the relationship between force, mass, and acceleration (Force = Mass × Acceleration). Understand that a larger force causes a larger acceleration, and a larger mass requires a larger force for the same acceleration.

  • Newton’s Third Law: Explain that for every action force, there is an equal and opposite reaction force.

Part D: The Force of Gravity

• Key Concepts: Mass vs. weight, gravitational force on Earth.

• Learning Goals:

  • Understand that gravity is a force of attraction between all objects with mass.

  • Differentiate between mass (the amount of matter in an object, measured in kg) and weight (the force of gravity on an object, measured in N).

  • Calculate the weight of an object on Earth using the formula: Weight = Mass × Gravitational Field Strength (where g ≈ 10 N/kg for Grade 7).

Part E: Friction and Its Effects

• Key Concepts: Types of friction, useful and harmful friction.

• Learning Goals:

  • Identify friction as a force that opposes motion between two surfaces that are in contact.

  • Describe different types of friction (static, sliding, rolling, fluid).

  • Analyze situations where friction is useful (e.g., walking, car brakes) and where it is harmful (e.g., engine wear, slowing down moving parts).

Curricular Competencies in Action (The “Doing” of Science)

• Questioning and Predicting:

  • “If you kick a soccer ball on grass versus on ice, why does it travel a different distance?”

  • “How does the mass of a toy car affect how fast it rolls down a ramp?”

• Planning and Conducting:

  • Lab: Ramp and Toy Cars. Students design an experiment to investigate how the height of a ramp (affecting force) or the mass of a car affects its speed at the bottom.

  • Investigation: Newton’s First Law with Inertia Towers. Quickly pull a index card out from under a coin to demonstrate an object at rest staying at rest.

• Processing and Analyzing Data and Information:

  • Calculate the average speed of various objects from collected distance and time data.

  • Construct and interpret distance-time graphs from motion data.

• Evaluating:

  • Compare different methods for reducing friction (e.g., wheels, lubricants, ball bearings) and evaluate their effectiveness in different scenarios.

• Applying and Innovating:

  • Design and build a simple device (e.g., a parachute, a balloon-powered car) that utilizes forces and motion principles.

• Communicating:

  • Use scientific language to explain the forces at play while riding a bicycle or a skateboard.

Sample Learning Standards from the BC Curriculum

• Content: “Explain the relationship between force, mass, and acceleration.”

• Content: “Measure and describe distance, time, and speed.”

• Content: “Compare the effects of balanced and unbalanced forces.”

• Curricular Competency: “Use scientific understandings to identify relationships and draw conclusions.”

Key Connections to Other Grade 7 Science Units

• Connection to Earth Science: The force of gravity is what holds planets in orbit around the sun and governs tides.

• Connection to Biology: The musculoskeletal system in animals (including humans) applies forces to create movement, directly linking to the physics of levers.

• Connection to Chemistry: The energy changes in chemical reactions can be harnessed to create forces (e.g., combustion in a car engine).

This unit provides a foundational understanding of the physics that govern everyday motion, from a ball rolling on the ground to the planets moving in space. It equips students with the tools to describe, measure, and explain the movement they observe in the world around them.