DSST Astronomy

# Explanation reflecting the reflecting telescope also

This preview shows pages 5–7. Sign up to view the full content.

Explanation: Reflecting. The reflecting telescope (also called a newtonian telescope) uses a curved mirror instead of a lens. Netwon's development of the use of mirrors instead of lenses opened the door to development of telescopes of millions of times magnification--far beyond what could ever be achieved with a lens. Newton's entire system is based on three laws of ____________. Explanation: Motion. These three laws are: 1. In the absence of outside forces, the momentum of a system remains constant. 2. If a force acts upon a body, the body accelerates in the direction of the force, its momentum changing at a rate numerically equal to that force. 3. Forces are always mutual, thus if a force is exerted upon a body, that body reacts with an equal and opposite force upon whatever exerts the force upon it. In 1905, Albert Einstein published a paper in which he outlined his theory of ______________. Explanation: Relativity. Einstein's theory was based on two postulates: 1. There is no absolute reference system with which we can measure absolute motions in space. The best we can hope to measure is the relative motion of one object with respect to another. 2. The speed of light, with respect to all observers, is always the same. The equatorial circumference of the Earth is ____________ statute miles. Explanation: 24,900. The Earth is not quite perfectly spherical. Along the Earth's equator one degree is about 60 nautical miles and a nautical mile is 1.1516 statute miles. The formula for figuring the circumference is 360 (degrees in a circle) x 60 (nautical miles in a degree) x 1.1516 (nautical miles in a statute mile). The study of stresses that build up gradually in the crust of the Earth and cause earthquakes is called ______________. Detailed Explanation: Seismology. Energy is often released by slippages along fissures or faults resulting in earthquakes. Some of these vibrations travel along the surface and others pass directly through the interior of the Earth. Seismology is studied through the use of instruments that pick up vibrations and record the activity. The ______________ increases about one degree Celsius for every one hundred feet you go downward into the crust of the Earth. Explanation: Temperature. As the core slowly cools, conduction gradually transmits heat from the Earth's interior out through the crust. Cooling of the hot core occurs at a very slow rate. The chemical composition of the Earth's atmosphere is mostly _____________. Explanation: Nitrogen. At the Earth's surface, the constituent gases are found to be 78 percent nitrogen, 21 percent oxygen, and 1 percent argon, with traces of water, carbon dioxide, and other gases. At lower elevations, variable amounts of dust particles and water droplets are also found suspended in the air.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
The Earth has a ______________ field similar to that produced by a bar magnet. Explanation: Magnetic. The magnetic poles of the Earth are located about 1200 miles from its geographical poles: the north magnetic pole is in Northeast Canada. The origin of this magnetic field is unknown, although it may be connected with the Earth's rotation and possibly with electrical currents in the interior.
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern