Sidebilder
PDF
ePub
[merged small][ocr errors][merged small][subsumed][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][ocr errors][ocr errors][ocr errors][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][ocr errors][ocr errors][ocr errors][merged small][ocr errors][merged small][merged small][subsumed][ocr errors][merged small][ocr errors][subsumed][merged small][merged small]

331.

=

2 +√ Qa−x)

Let (s) be the space required; then the whole time

of descent (t) is expressed by

[blocks in formation]

2. (2t - 9)

[ocr errors]

and that described in the last second but 4, is

L. {(t —

g

2

{ (t − 4)2 — (t − 5)o} =

[merged small][ocr errors][merged small][merged small][merged small][ocr errors][ocr errors][merged small][ocr errors][merged small][merged small][merged small]

g

332.

Let t be the time required. Then by the expression

for the circumstances of motion on inclined planes,

[merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small]

333.

Let Aa, Bb (Fig. 88) be the perpendiculars to the horizon bT. Then, joining AB let it be produced to meet ba in T, and take TP a mean proportional between TA, TB, and describe the circle APB passing through A, P, B, and join AP, PB, P is the point required.

[merged small][merged small][ocr errors]

the circle touches the horizon in P.

Hence time down BP time AP.

The point B will fall within or without ab according as the arc or < 10.

PAB is > or

334.

Let AB = a, AC = 6, and the distance fallen by

the latter body before it is overtaken = x; then

b-a + x

is the distance fallen by the former in the same time t with the velocity (v) acquired at B. Hence

[blocks in formation]
[ocr errors][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small]

335.

If be the inclination of the plane, the moving force

[blocks in formation]

in the time t, the inclination of the plane being any whatever.

[merged small][merged small][merged small][ocr errors][merged small]

336.

Let t be the time in which the bodies meet, a the distance between the points of projection, and from the upper of these let x be the distance of the point of concourse; then

[merged small][ocr errors][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small]

THE GRAVITATION OF BODIES.

=

v'2 — v2 = ga = (ga) the square of the velocity

[blocks in formation]

337.

Let a be the inclination of the given plane to the horizon, of that sought; then the moving force is

P. sin. α- W sin.

and the accelerating force (9) is

P

P sin. a W sin. 0

P+W

[merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small]

338. Here the moving force is evidently 1 oz, and.. the accelerating force is @ = by avoirdupoise weight.

1

33

[merged small][ocr errors][ocr errors][ocr errors][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][ocr errors][merged small][merged small][merged small][merged small][merged small]
[merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][ocr errors][merged small][ocr errors][merged small][merged small][ocr errors][ocr errors]

340.

Let a be their distance at first, x that after the lapse

of the time t; then since the spaces described in that time are

[merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small]

Now when the bodies meet x = 0, and ..t=

[ocr errors][merged small]
[ocr errors][merged small][merged small]
[merged small][merged small][ocr errors][merged small][ocr errors][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][ocr errors][merged small][merged small][ocr errors][ocr errors][merged small][merged small][merged small]

Here the moving force is 1 oz. and, by the question,

342. we have, therefore,

« ForrigeFortsett »