304 Molesworth’s pocket-book
Force—continued.
The weight of 1 gramme = 981 dynes.
„ 1 grain = 63’57 „
■ 1 oz.avoir. = 2'78 x 104 dynes.'
■ lib. ‘
■ „ 1 cwt.
■ 1 ton
= 4-45 x 105 „
= 4-98 X 10' „
= 9-97 X 108 „
One poundal = 13,825 dynes. '
Work or Energy:—
The C. G. S. unit of work or energy is called the
erg; and is the amount of work clone by a dyne
working through a distance of a centimetre.
1 gramme-centimetre
1 gramme-metre
1 kilogrammet re
’ milligram-millimetre
1 foot-pound
— 981 ergs.
= 981 x IO2 ergs.
= 981 x 105 „
= -0981 „
= (13825 X </) = 1-356
X 107 ergs.
= 421,390 ergs.
— 3-04 X IO10 ergs.
— 7'46 x 10’ ergs a sec.
1
= 479 dynes a sq. cm.
= 6'9 x IO4 „
ergs.
1 foot-poundal
1 foot-ton
1 horse-power
Pressure:—
1 pound a square foot
1 pound a square inch
1 kilogramme per sq. m. = 98 ‘ 1 „
760 mm. mercury at 0° C. — 1'014 x 106 „
30 ins. „ „ = 1-0163 X 10« „
Heat
1 gramme-degree Cent. = 4'2 X 107
2 pound-degree „ = 1*91 x 1010
3 „ Fahr. = 1-06 X 1010
Electricity:—
4 volt-weber = 7|^HP. = 10' ergs.
* To avoid confusion in writing numerous ciphers, this
notation has been generally adopted; 10" means 10 to the nth
power, or 1 with as many ciphers after as n indicates; thus
104 = 10,000.