成人快手

  • Physics

    • Waves

      Waves are all around us. It鈥檚 normal to think of waves in the sea but waves are also in the air, in space, under your feet and in your ears and eyes.

    • Light Waves

      Light is a type of electromagnetic radiation that can be detected by the eye. It travels as a transverse wave.

    • Sound Waves

      Sound waves are produced by a vibrating object. Everything that makes a sound must have a part that vibrates.

    • Physical change

      Physical changes such as state change and dissolving are reversible, and there is no change in total mass when they happen.

    • Heat transfer

      Temperature and heat are not the same. Heating matter makes the particles vibrate faster or move faster.

    • Forces, Pressure and Speed

      A force is a push or a pull. For example, when you push open a door you must apply a force to the door. You also must apply a force to pull open a drawer.

    • Energy

      Energy is essential for every one of us. Humans have advanced because we have learned how to change energy from one form into another.

    • Earth and space

      The Earth travels through space and through time. It is part of a solar system with a star called the Sun at the centre.