GCSE Science A Physics 1 Waves Radioactive sources Radioactive sources need to be handled very carefully. The following safety precautions need to be taken: Never look directly at the source Always use tongs Keep source at arms length Record how long you have been exposed for Store radioactive sources in a lead lined box (below) Wear eye protection at all times Radioactive sources need to be handled very carefully. The following safety precautions need to be taken: Never look directly at the source Always use tongs Keep source at arms length Record how long you have been exposed for Store radioactive sources in a lead lined box (below) Wear eye protection at all times In addition to the above, in industry, the following precautions may also be taken: Wear protective (lead lined) clothing Nuclear waste must be stored in lead barrels deep underground In addition to the above, in industry, the following precautions may also be taken: Wear protective (lead lined) clothing Nuclear waste must be stored in lead barrels deep underground

GCSE Science A Physics 1 Waves The Electromagnetic Spectrum All EM Waves; Travel at the speed of light (3x10 8 m/s). All carry Energy and Information. All EM Waves; Travel at the speed of light (3x10 8 m/s). All carry Energy and Information.

GCSE Science A Physics 1 Waves The Electromagnetic Spectrum UsesDangers Used for communicating over vast distances Transmitting TV and radio programmes

GCSE Science A Physics 1 Waves The Electromagnetic Spectrum UsesDangers Heating food. Some people are concerned about possible health risks with the signals from mobile phones. In particular; long term exposure for children Mobile phone signals

GCSE Science A Physics 1 Waves Waves and communication Satellite Communications Geostationary orbit: Satellite orbits above the same point on the Earth at all times The satellite takes 24 hours to orbit the Earth. Satellites (mainly) use microwaves to communicate with base stations on Earth. Fibre Optic Cable Use infrared to send information down special cable using “total internal reflection” Speed of infrared radiation in the cable is 2x10 8 m/s Satellite Communications Geostationary orbit: Satellite orbits above the same point on the Earth at all times The satellite takes 24 hours to orbit the Earth. Satellites (mainly) use microwaves to communicate with base stations on Earth. Fibre Optic Cable Use infrared to send information down special cable using “total internal reflection” Speed of infrared radiation in the cable is 2x10 8 m/s

GCSE Science A Physics 1 Waves The Electromagnetic Spectrum UsesDangers Heating food (toasters, grills) Can cause skin burns Heating people (patio warmers) Remote controls Fibre-optic cables (broadband)

GCSE Science A Physics 1 Waves The Electromagnetic Spectrum UsesDangers Seeing Can cause eye damage if very bright Communication CD-players and Blu-Ray Lasers

GCSE Science A Physics 1 Waves The Electromagnetic Spectrum UsesDangers Used to sterilise water.Can ionise skin cells causing sunburn and skin cancer. Detected forged notes Sick RavesCan cause eye damage (cataracts)

GCSE Science A Physics 1 Waves The Electromagnetic Spectrum UsesDangers Medical ImagingX-rays are highly ionising, and can cause cancer anywhere within the body. Detected by some space telescopes.

GCSE Science A Physics 1 Waves The Electromagnetic Spectrum UsesDangers Used for medical imagingGamma Rays are highly ionising, and can cause cancer anywhere within the body. Sterilisation of medical equipment Chemotherapy