Step-by-step explanation:
Using the law of the conservation of linear momentum P:
P_i = P_fP
i
=P
f
so:
M_mV_{mi}+M_pV_{pi} = M_sV_sM
m
V
mi
+M
p
V
pi
=M
s
V
s
where M_mM
m
is the mass of the man, V_{mi}V
mi
is the initial velocity of the man, M_pM
p
is the mass of the puck, V_{pi}V
pi
is the initial velocity of the puck, M_sM
s
is the mass of the puck and the man and V_sV
s
is the velocity of both after the collition.
Replacing values, we get:
(80kg)(0m/s)+(0.17kg)(20m/s) = (80kg + 0.17kg)V_s(80kg)(0m/s)+(0.17kg)(20m/s)=(80kg+0.17kg)V
s
Finally, solving for V_sV
s
:
V_sV
s
=0.0424m/s