Physics

Class 7: Sound
•Sound is a vibration we can hear. •A vibrating object makes sound •Sound travels through air. It travels more quickly through solids than liquids or gases •Speed of sound in air = 330m/s
SI Units
SI units are an International System of units that are recognized and used in calculations by scientists world wide. Fundamental SI Units 1. Length - SI Unit is meters with the symbol m.
Class 7: Forces
•A force is a push or pull on a body. •Force causes motion: change in speed, direction, shape or size. •SI Unit of Force: Newton : N Types of forces:
Class 7: Electricity
An electric circuit is a path for electric charge (electrons) to flow along. Circuit Symbols Series and Parallel Circuits In a series circuit, all circuit components are connected in one single loop.
Class 7: Energy & Changes
Energy from food Energy is measured in Joules. We get energy from food. Energy in foods is measured in kiloJoules. It is also measured in kilo Calories. 1 kCal = 4 kJ Different people have different energy requirements per day: