fisica1-youn-e-freedman-exercicios-resolvidos

1.75: Let +x be east and +y be north. Let A r o
be the displacement 285 km at 40 .0 north
of west and let B r be the unknown displacement.
r r r r
A + B = R,
where R = 115 km,
r r r
B = R − A
B
A
R
x
x
x
= −Acos 40.0
= 115 km, R
Then B
B =
= R
x
B
x
2
x
− A
x,
= 0
= 333.3 km, B
+ B
2
y
B
y
y
= R
o
y
− A
= −218.3 km, A
y
= 380 km.
y
east
= −183.2 km.
y
= + A sin 40.0
o
= + 183.2 km
tanα
= B
y
B
=
o
α = 28.8 , south of east
x
( 183.2km) ( 333.3 km)
1.76:
(a)
(b)
(c)
ω
ω
ω
par
perp
par
= ω sinα
= ω cosα
= ω sinα
ωpar
550 N
ω = =
sinα
sin 35.0
0
= 960 N