# Theoretical Mechanics for Junior Students

By (author)

List price: US\$13.91

Currently unavailable

AbeBooks may have this title (opens in new window).

## Description

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1872 edition. Excerpt: ...place, g = Tt3/. If l be taken in inches, of course g will be found in inches also. 145. Inequality of the Force of Gravity at Different Places.--Pendulum experiments show that the force of gravity varies over the surface of the earth. At London, the value of j is 32-191; at the equator, 32088; at Spitzbergen, 32'252. This is due to two causes. The centrifugal force at the equator is very great, and balances a certain portion of the force of gravity. At the poles centrifugal force is nothing, and therefore gravity acts with full force there. Again, places on the equator are farther from the centre of gravity of the earth than places at the poles; therefore, gravity acts upon them less powerfully. A point on the equator is 13 miles farther from the centre than the north pole. Therefore, so far as this cause is concerned, the force of gravity at the equator is to its force at the pole as /7913. /7939N. It was by pendulum experiments in different parts of the world that the spheroidal form of the earth was demonstrated. Sir Isaac Newton conjectured that it must be oblate, from its rotation on its axis; and this was proved by pendulum observations, and afterwards by the discovery that a degree of a meridian near the pole is about half-a-mile longer than a degree near the equator. EXAMINATION QUESTIONS. 1. Explain what is meant by centrifugal force; and show how it is measured. 1861. 2. When a pendulum is set vibrating, why does it not stop when it comes to the lowest point? A chandelier hangs from a high roof, and is itself 20 ft. from the ground. It makes five vibrations in 41." What is the height of the roof? 1862. 3. Explain the action of a pendulum, and show that the time of vibration is proportional to the square root of...show more

## Product details

• Paperback | 38 pages
• 189 x 246 x 2mm | 86g
• United States
• English
• black & white illustrations
• 1236989570
• 9781236989574