QUES: Take a look at this train in Figure 1.11. It looks very futuristic. What do you notice about it? Did you notice that the train has no wheels? How can a train have no wheels? It doesn't need wheels. It actually floats, or levitates, just above the track. Magnets enable the train to do this. This is not a normal train. This is a maglev train. The word maglev stands for magnetic levitation. Because it has no wheels, there is no friction. Some magnets hold the train up. Other magnets are used to move the train forward. This train can go very fast. It can reach speeds up to 480 kilometers (300 miles) per hour! Magnets are pretty cool. What exactly is a magnet? How is it able to exert such force?
Do you have any questions?
MY QUESTION: What do you notice about figure 1.11?

QUES: But I think it is certain that most of the early Christians understood these words of our Lord's ascension and coming again in glory. They believed that He was coming again in a very little while during their own life-time, in a few months or years, to make an end of the world and to judge the quick and the dead. And as they waited for His coming, one generation after another, and yet He did not come, a sadness fell upon them. Christ seemed to have left the world. The little while that He had promised to be away seemed to have become a very long while. Hundreds of years passed, and yet Christ did not come in glory. And, as I said, a sadness fell on all the Church. Surely, they said, this is the time of which Christ said we were to weep and lament till we saw Him again--this is the time of which He said that the bridegroom should be taken from us, and we should fast in those days. And they did fast, and weep, and lament; and their religion became a very sad and melancholy one--most sad in those who were most holy, and loved their Lord best, and longed most for His coming in glory.
Do you have any questions?
MY QUESTION: Who did sadness fall upon awaiting the coming of Christ?

QUES: Electric charge is a physical property. It occurs between particles or objects. It causes them to attract or repel each other. They do not even have to touch. This is unlike the typical push or pull you may be familiar with. All electric charge is based on the protons and electrons in atoms. A proton has a positive electric charge. An electron has a negative electric charge. Forces on Charged Objects Most atoms are balanced electrically. They have the same number of positive and negative charges. Therefore, the number of protons equals the number of electrons. Neutrons do not matter as they have no charge. When an object loses some electrons, it becomes positively charged. There are now more protons than electrons inside the atom. The lost electrons may remain free. Or, they may attach to another object. The new object now has more electrons than protons. It then becomes negatively charged.
Do you have any questions?
MY QUESTION: What kind of charge does an atom with more electrons than protons have?

QUES: The highest point of a wave is the crest. The lowest point is the trough. The vertical distance between a crest and a trough is the height of the wave. Wave height is also called amplitude. The horizontal distance between two crests is the wavelength. Both amplitude and wavelength are measures of wave size. The size of an ocean wave depends on how fast, over how great a distance, and how long the wind blows. The greater each of these factors is, the bigger a wave will be. Some of the biggest waves occur with hurricanes. A hurricane is a storm that forms over the ocean. Its winds may blow more than 150 miles per hour! The winds also travel over long distances and may last for many days.
Do you have any questions?
MY QUESTION:
What are the highest and lowest points of a wave?