fisica1-youn-e-freedman-exercicios-resolvidos

8.14: The impluse imparted to the player is opposite in direction but of
the same magnitude as that imparted to the puck, so the player’s speed is
= 4.27 cm/s, in the direction opposite to the puck’s.
(0.16 kg) (20.0 m s)
(75.0 kg)
8.15: a) You and the snowball now share the momentum of the snowball
(0.400 kg) (10.0 m s)
when thrown so your speed is = 5.68 cm s.
(70.0 kg+ 0.400 kg)
b) The change in
the snowball’s momentum is
your speed is
7.20 kg⋅m s
70.0 kg
= 10.3 cm/s.
( 0.400 kg) (18.0 m s) = 7.20 kg ⋅ m s), so
8.16: a) The final momentum is
( 0.250 kg)( − 0.120 m s) + (0.350)(0.650 m s) = 0.1975 kg ⋅ m s,
taking positive directions to the right. a) Before the collision, puck B was
at rest, so all of the momentum is due to puck A’s motion, and
b)
∆ K
= K
2
p 0.1975 kg ⋅ m/s
v
A1 = =
= 0.790 m/s.
mA
0.250 kg
1 2 1 2 1 2
− K1
= mAv
A2
+ mBvB2
− mAv
A1
2 2 2
1
2 1
= (0.250 kg) ( −0.120 m s) + (0.350 kg)(0.650 m s)
2
2
1
2
− (0.250 kg)( −0.7900m s)
2
2
= −0.0023 J