How does a refrigerator cool food? By transferring the heat from inside the refrigerator to outside using evaporation. Fresh foods have to be kept cool to make them last longer. As soon as they are opened, or cut, bacteria start to decompose them. When foods decompose, they taste bad, but some bacteria can produce toxins […]
#320 How does a refrigerator cool food? Read More »
Why does metal spark in a microwave oven? The microwave charges one side of the metal positively and one side negatively. This charge can ionize the air, making sparks. First, we need to look at what microwaves are. A microwave is a type of electromagnetic radiation. Electromagnetic radiation is energy that moves in waves and
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How does a steam engine work? By taking the energy contained in coal and making heat. Then using the heat to turn water into steam and using the steam to push and pull a piston. The steam engine was the invention that helped push the Industrial Revolution. However, the knowledge of steam power has been
#316 How does a steam engine work? Read More »
How tall could a skyscraper be? Theoretically 69.1 km tall, but practically, about 2 km. The tallest building in the world at the moment is the Burj Khalifa. It is 830 meters tall. For over 3800 years, the tallest building in the world was the Great Pyramid at Giza. It was 147 meters tall when
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How does an electroencephalogram work? By measuring electrical activity in different parts of the brain using electrodes on the scalp. EEGs are used to diagnose disorders with the electrical activity in the brain. These can be epilepsy, sleep disorders, anesthesia, coma, and even brain death. It is most commonly used for diagnosing epilepsy, which is
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Is nuclear waste dangerous? It is if it isn’t handled properly. This was interesting to research. All of the sites I looked at that were run by nuclear organizations said, “no, no, of course not,” while the sites I looked at from other sources said, “possibly.” When we think about nuclear waste, we think about
#309 Is nuclear waste dangerous? Read More »
How does an AED work? It has sensors to detect the rhythm of the heart and it has a powerful battery to deliver a shock to correct the heart. AED stands for Automatic External Defibrillator. It is a defibrillator that is automatic. So, let’s start by finding out what a defibrillator is. A defibrillator is
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Why are we running out of helium? It is a non-renewable resource that we are rapidly using up. Many people don’t give a second thought about helium. It is the second lightest element and the second most abundant element in the universe after hydrogen. It is thought to make up 24% of the total elemental
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Why can we only hear certain frequencies? Our cochlea is only stimulated by frequencies between 20 Hertz and 20,000 Hertz. First, let’s look at how we actually hear. Our ear is a detector for sound waves. It is shaped to funnel them into the ear canal, which ends in the eardrum. The sound waves make
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Could nuclear fusion power the Earth? Yes, but not in this half of the 21st century. Nuclear fusion and nuclear fission are the two ways we can get energy out of an atom. Nuclear fission is the easiest of the two for us to perform on Earth. In nuclear fission, a neutron is fired at
#296 Could nuclear fusion power the Earth? Read More »
