What is electromagnetic wave made of

The speed of light in a certain substance is 83% of its value in water. what is the index of refraction of this substance?

Which best describes direct current? A. It requires constant temperatures to flow. B. It regularly reverses direction. C. It requires multiple voltage sources to flow. D. It flows only in one direction.

1. A ray of light traveling from air into crown glass strikes the surface at an angle of 30 degrees. What will the angle of refraction be?

when a book falls from a shelf to the ground without anyone pushing on it, no work is done on the book. true or false

a ball is dropped from rest at a 80m above the ground. How long does it take for it to reach the ground?

Why does momentum have a direction?

What is the difference between weight and mass?

An object has a mass of 8.00 kg. What is the gravitational force on the object by the earth?

Which of the following best characterizes the free energy change ΔG for an endothermic reaction under physiological conditions? A. The sign of ΔG is positive B. The sign of ΔG is zero C. The sign of ΔG is negative D.

In a recent hockey game, one player (m=100kg) was moving at a velocity of 8 m/s when he ran into another player (m=300kg) who was at rest (v=0m/s). After the collision, the two players were stuck together (moving with the same velocity).