fisica1-youn-e-freedman-exercicios-resolvidos

4.29: tricycle and Frank
T is the force exerted by the rope and f
g
is the force the ground exerts on the tricycle.
spot and the wagon
T ′ is the force exerted by the rope. T and T ′ form a third-law action-reaction pair,
T r
= −T
r ′.
x x 2(0.130 m)
4
4.30: a) The stopping time is = v
= = 7.43×
10 s.
result.)
vave
−
( 0 / 2) 350 m / s
−3
(350 s)
b) (1.80 10 kg)
m /
2
F = ma = ×
848 N.
(Using a = v / 2x
gives the same
- 4 =
(7.43×
10 s)
0
4.31: Take the + x -direction to be along F r 1
and the + y -direction to be along R r . Then
F
2x
= −1300N and F
2 y
= 1300 N , so F = 1838
2
N , at an angle of 135 ° from F r 1
.
4.32: Get g on X:
1 gt
y = 2
2
1
2
10.0m
= g(2.2 s)
2
g = 4.13 m /
2
s
2
w
X
= mg
X
= (0.100 kg)(4.03 m / s ) = 0.41N