v0 ą
mg
b)
XY
3
t (x(t), y(t)).
t : (x (t), y (t)), t : x (t), y (t)),
(0, -mg), (-bx (t), -by (t)).
-

-
m = F ,
a
-

-

a F
mx (t) = -bx (t),
my (t) = -mg - by (t).
y,
x.
x(0) = 0, y(0) = 0
t = 0
-

(x (0), y (0)) = v0 = (v0 cos ą, v0 sin ą).
x = z. z = -bz,
b
z(t) = C exp - t ,
m
m b
x(t) = C1 - C exp - t .
b m
m
0 = x(0) = C1 - C v0 cos ą = x (0) = C,
b
x
mv0 b
x(t) = cos ą 1 - exp(- t) .
b m
y x,
my = -by
m b
y(t) = C1 - C exp - t .
b m
y0(t) = -mgt/b
t
m b mg
y(t) = C1 - C exp - t - t.
b m b
m
0 = y(0) = C1 - C,
b
mg
v0 sin ą = C - .
b
mv0 m2g b mg
y(t) = sin ą + 1 - exp(- t) - t.
b b2 m b
mv0 b
x(t) = cos ą 1 - exp(- t)
b m
mv0 m2g b mg
y(t) = sin ą + 1 - exp(- t) - t
b b2 m b
t
x, y(t) = 0 y(0) = 0),