fisica1-youn-e-freedman-exercicios-resolvidos

2.41: a) If the meter stick is in free fall, the distance d is related to the reaction time t by
2
d = ( 1 2) gt , so t = 2d
g.
If d is measured in centimeters, the reaction time is
t =
2 2
g
d
=
2
−
d = (4.52×
10 s) d (1cm).
2
980 cm s
2
b) Using the above result, (4.52× 10
− s) 17.6 = 0.190 s.
2
2
2
2.42: a) (1 2) gt = (1 2)(9.80 m s )(2.5 s) = 30.6 m.
2
b) gt = (9.80 m s )(2.5s) = 24.5.m s .
c)