Setting posts is tricky—you typically need a solid base and a top that is completely level, which is difficult when the base of a post is sitting on an angle. Here's a great tip for obtaining the ...

Refraction close refractionProcess by which a wave changes speed and sometimes direction upon entering a denser or less dense medium, eg a light ray changes direction when refracted by a lens. of ...

There are different ways to investigate refraction in rectangular blocks. In this required practical activity, it is important to: make, measure and record the angles of incidence accurately using a ...

Smartphones are useful for a lot of things. You can even use one as a ruler in a pinch. Generally speaking, you won’t replace your trusty yard stick. A phone is simply too small for anything other ...