The Gravity Unit of Force
المؤلف:
GEORGE A. HOADLEY
المصدر:
ESSENTIALS OF PHYSICS
الجزء والصفحة:
p-56
2025-10-23
23
Instead of using absolute units, we may measure forces by comparing them with the weight of a standard mass. A force of 1 pound, for instance, means a force equal to the force by which a mass of 1 pound is pulled downward by gravity. The pound, as a gravity unit of force, is therefore equal, at New York, to 32.16 poundals; and the gram to 980.2 dynes. As the force of gravity varies at different places, the gravity unit of force is variable. The pound, however, everywhere equals g poundals, and the gram everywhere equals g dynes.
in which W is the weight of the body moved. If W is expressed in absolute units. (= Mg), the result F will be expressed in absolute units; but if, as is usual, W is expressed in gravity units (= M), then F will be expressed in gravity units.
For instance, to measure the force that will be required at New York to impart in one second a velocity of 20 feet per second to a mass of 160 pounds, we write
الاكثر قراءة في وحدات القياس الفيزيائية
اخر الاخبار
اخبار العتبة العباسية المقدسة
