Why are electromagnets stronger than permanent magnets? Because the amount of current and the number of coils in the copper wire can increase the strength of an electromagnet while a permanent magnet cannot be any more magnetic than it already is. The strength of a magnet is measured in different ways, but one way is […]
#693 Why are electromagnets stronger than permanent magnets? Read More »
How does ceramic armor work? It shatters the projectile, absorbing and spreading out the kinetic energy from the projectile over a wider area. The first thing to clear up is that ceramic armor plates are made of a different type of ceramics than the mugs and cups in your kitchen. There are many different types
#682 How does ceramic armor work? Read More »
Why do tattoos stay in the skin forever? Because the particles of ink are too big for the body to absorb and expel. When you have a tattoo, the tattooist uses a needle to put ink particles into your skin. Skin has three layers, and the ink is injected into the middle layer, the dermis.
#681 Why do tattoos stay in the skin forever? Read More »
How does insulation in the home work? By slowing down the movement of heat energy out of the house or into the house. The idea of insulation is to stop your house getting cold in the winter or hot in the summer. If you live somewhere that is cold in winter, you have to use
#680 How does insulation in the home work? Read More »
What are food additives? They are things that are added to food to preserve the flavor, or improve the taste, appearance, or other qualities. There are a huge number of food additives and some of them are completely natural. Salt and sugar are both food additives. Humans have been using food additives ever since we
#667 What are food additives? Read More »
Too busy to read? Watch on YouTube Why do ducks float? They float because of their center of gravity, their hollow bones, the air in their feathers and air sacs, and the oil on their feathers. Whether or not something floats has to do with the object’s density and the buoyancy of water. Water has
#662 Why do ducks float? Read More »
Watch on YouTube How was the meter (metre) defined? In 1791 it was defined as one ten-millionth of the distance from the equator to the North Pole. The word “meter” comes from Greek and means “to measure” or “to count.” That’s why the “meter” in speedometer and altimeter doesn’t mean the unit of distance. The
#655 How was the meter (metre) defined? Read More »
Watch on YouTube Why does blood show up under UV light? Because it absorbs all of the light and appears completely black. When we watch crime movies, the police often use a black light to show stains at the murder scene. Well, a black light will make many bodily fluids glow, but it won’t make
#652 Why does blood show up under UV light? Read More »
Watch on YouTube How much wind does a wind turbine need? A wind speed of roughly 11 km/h. Wind power has been used for over 2000 years. The windmill was invented in the 7th century in Persia and wind power was harnessed to grind grain. The wind could do the work of a herd of
#649 How much wind does a wind turbine need? Read More »
Watch on YouTube How does an iron remove wrinkles from clothes? The heat forces the cellulose chains to lie straight. People started wearing clothes about 170,000 years ago. Scientists worked this out by looking at the evolution of lice that live on humans. Lice that live on clothes are different from the lice that live
#644 How does an iron remove wrinkles from clothes? Read More »
