.
P s, ,
(1)A = Ps cos α,
α .
α = 90
cos α = cos 90 = 0 A = 0,
. . , , .
, α = 0, cos α = cos 0 = 1 (1) :
(1')A = Ps.
, , (. . , 83):
(2)AR = ∑ Ai,
. . - .
, ( ), , , AR=0. (2)
(2')∑ Ai = 0,
. . .
, , , , , . , , .
, , , ().
1. , , P, (1) (1') .
2. P, Ap (2) (2'), .
, ,
(3)N = A/t N = (Ps cos α)/t.
v=s/t ,
(3')N = Pv cos α.
, s/t = v (2')
N = Pv cos α.
(. . .)
(4)η = A/A,
A ; A , :
(4')η = N/N.
1 () = 1 * 1 .
1 () = 1 / 1 .
(. .):
1000 = 1,36 . . 1 . . = 736 .
N () = 1,36 N (. .)
N (. .) = 0,736 N ().
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221. , 4 50 ? ...
222. M m=40 , , P, ...
223. , m=1200...
224. , s 1 ...
225. G=50 , l=4 α=20 (. 255,...
227. G=50 l=4 α=20. , ...
229. , , 50 4 ...