QUES: Renewable Energy Resource Sunlight Sunlight can be used to heat homes. It can also be used to produce electricity. This conversion is made possible by solar cells. However, solar energy may not always be practical. Some areas are just too cloudy. Example Solar panels on the roof of this house generate enough electricity to supply a familys needs. Moving Water Falling water can have a lot of energy. Its energy can be converted into kinetic energy. This energy can turn a turbine and generate electricity. The water may fall naturally over a waterfall or flow through a dam. A drawback of dams is that they flood land upstream. They can also reduce water flow downstream. Either effect may harm ecosystems. Wind Wind is moving air. It has kinetic energy that can do work. Wind turbines change the kinetic energy of the wind to electrical energy. Only certain areas of the world get enough steady wind. Many people also think that wind turbines are noisy and not very nice to look at.
Do you have any questions?
MY QUESTION: What is the drawback of kinetic energy from hydro power?

QUES: Earths magnetic field helps protect Earth and its organisms. It protects us from harmful particles given off by the sun. Most of the particles are attracted to the north and south magnetic poles. This is where Earths magnetic field is strongest. This is also where relatively few organisms live. Another benefit of Earths magnetic field is its use for navigation. People use compasses to detect Earths magnetic north pole. Knowing this helps them tell direction. Many animals have natural 'compasses' that work just as well. Birds like the garden warbler in Figure 1.36 use Earths magnetic field. They use it to guide their annual migrations. Recent research suggests that warblers and other migrating birds have structures in their eyes. These structures let them see Earths magnetic field as a visual pattern.
Do you have any questions?
MY QUESTION: Where is Earths magnetic field strongest?

QUES: As his car slid downtown on Tuesday morning the mind of Arnold Thorndike was occupied with such details of daily routine as the purchase of a railroad, the Japanese loan, the new wing to his art gallery, and an attack that morning, in his own newspaper, upon his pet trust. But his busy mind was not too occupied to return the salutes of the traffic policemen who cleared the way for him. Or, by some genius of memory, to recall the fact that it was on this morning young Spear was to be sentenced for theft. It was a charming morning. The spring was at full tide, and the air was sweet and clean. Mr. Thorndike considered whimsically that to send a man to jail with the memory of such a morning clinging to him was adding a year to his sentence. He regretted he had not given the probation officer a stronger letter. He remembered the young man now, and favorably. A shy, silent youth, deft in work, and at other times conscious and embarrassed. But that, on the part of a stenographer, in the presence of the Wisest Man in Wall Street, was not unnatural. On occasions, Mr. Thorndike had put even royalty frayed, impecunious royalty, on the lookout for a loanat its ease. The hood of the car was down, and the taste of the air, warmed by the sun, was grateful. It was at this time, a year before, that young Spear picked the spring flowers to take to his mother. A year from now where would young Spear be? It was characteristic of the great man to act quickly, so quickly that his friends declared he was a slave to impulse. It was these same impulses, leading so invariably to success, that made his enemies call him the Wisest Man. He leaned forward and touched the chauffeur's shoulder. "Stop at the Court of General Sessions," he commanded. What he proposed to do would take but a few minutes. A word, a personal word from him to the district attorney, or the judge, would be enough.
Do you have any questions?
MY QUESTION: What did Mr. Thorndike want to do at the Court of General Sessions?

QUES: Density is also an important physical property of matter. The concept of density combines what we know about an objects mass and volume. Density reflects how closely packed the particles of matter are. When particles are packed together more tightly, matter is more dense. Differences in density of matter explain many phenomena. It explains why helium balloons rise. It explains why currents such as the Gulf Stream flow through the oceans. It explains why some things float in or sink. You can see this in action by pouring vegetable oil into water. You can see a colorful demonstration in this video.
Do you have any questions?
MY QUESTION:
What are some things density explains?