Homework 2 Solution
Components
34, 313
Adding subtracting 320
Unit vectors 321
Position, displacement, velocity, acceleration 333, 334, 336,
Relative motion 343, 358
34.
•
Find the
x
and
y
components of a position vector,
G
r
, of magnitude
(r=75m
)if its angle relative to the
x
axis is
(a)
t
h1=35.0°
and
(b) th2= 85.0°
.
sol34.(a)
cos
(75 m)cos35.0
61 m
x
rr
θ
==
°
=
sin
(75 m)sin35.0
43 m
y
°
=
(b)
(75 m)cos85.0
6.5 m
x
r
=°
=
(75 m)sin85.0
75 m
y
r
=
313•• A whale comes to the surface to breathe and then dives at an angle of
(
th=20.0°
)below the
horizontal. If the whale continues in a straight line for 150 m,
(a)
how deep is it, and
(b)
how far has it
traveled horizontally?
Sol
313.
y
= depth of whale
x
= distance traveled horizontally
(a)
sin
(150 m)sin(20.0 )
51 m deep
yr
°
=
(b)
cos
(150 m)cos(20.0 )
140 m
xr
°
=
20.
•• A basketball player runs down the court, following the path indicated by the vectors
G
G
G
AB
C
,,
and
in
Figure 3–35.
The magnitudes of these three vectors are: A= (10.0) m, B=
(20.0)m, and C= (7.0)m Find the magnitude and direction of the net displacement of the player
using
the component method of vector addition.
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View Full DocumentSolution 320
ˆˆ
[0 (20.0 m)cos45
(7.0 m)cos( 30 )]
[( 10.0 m) (20.0 m)sin 45
(7.0 m)sin( 30 )]
(20 m)
(0.60 m)
++= +
°
+
−° +−
+
°
+
−°
=+
ABC
x
y
xy
GG
G
22
1
(20 m)
(0.60 m)
20 m
0.60 m
tan
20 m
1.7
θ
−
++ =
+
=
=
=°
G
321.
•
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 Fall '09
 WOODAHL
 Physics, Acceleration, Work, Velocity, Sin, Ry, s⎠ s⎠

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