fisica1-youn-e-freedman-exercicios-resolvidos

3.16: a) Solving Eq. (3.18) with y = 0,
y = 0
0.75m
gives t = 0.391s
.
b) Assuming a horizontal tabletop, v 0 , and from Eq. (3.16),
v ( ) /
x
= x − x0 t 3.58m s .
0
=
0 y
=
c) On striking the floor, = −gt
= − 2gy0 = −3.83m s , and so the ball has a velocity
v y
of magnitude 5 .24m s , directed 46 .9°
below the horizontal.
d)
Although not asked for in the problem, this y vs. x graph shows the trajectory of the
tennis ball as viewed from the side.
2
3.17: The range of a projectile is given in Example 3.11, = v sin α g .
2
R
0
2
0
2
2
a) (120 m s) sin110° (9.80 m s ) = 1.38 km .b) (120 m s) sin110° (1.6 m s ) = 8.4 km .
2