When a block with a hole in it is heated why does not the material around the hole expand into the hole and make it small

Why do radio waves diffract around buildings, while light waves do not?

Which statement is most accurate? A - The greater the physical density of a material, the higher the refractive index. B - The greater the optical density of the material, the lower the refractive index.

A common demonstration involves charging a rubber balloon, which is an insulator, by rubbing it on your hair and then touching the balloon to a ceiling or wall, which is also an insulator.

Describe the pattern of air circulation between an area of low pressure and high pressure

An electrical short cuts off all power to a submersible diving vehicle when it is a distance of 28 m below the surface of the ocean. The crew must push out a hatch of area 0.70 m2 and weight 200 N on the bottom to escape. If the pressure inside is 1.

Why can we see our breath on a cold winter day

True or false describing a metal as malleable means that it can be pounded into a new shape

A 40 kg-skier starts at the top of a 12-meter high slope. At the bottom, she is traveling 10 m/s. How much energy does she lose to friction? A. She doesn't lose any because mechanical energy is always conserved. B. 4,704 J C. 2,000 J D. 2,704 J

In a series circuit, loads which have the same voltage dropped across them will have?.

Which of the following describes temperature