Answer:
x = 0.0756 m
Fred moves in the direction where Brutus moves
Explanation:
This exercise is for the moment, we define the system as formed by the two players, for this system the forces in the clash are internal, so the moment is preserved
Initial. Before the crash
p₀ = m v₀₁ - M v₀₂
Final. After the crash
= (m + M) v
p₀ =
m v₀₁ –M v₀₂ = (m + M) v
v = (m v₀₁ - M v₀₂) / (m + M)
Let's calculate
v = (60 6 - 120 4) / (60 +120)
v = - 120/180
v = - 0.667 m / s
The negative sign indicates that the final speed is the direction where Brutus runs
Let's use Newton's second law to find the acceleration of the two players
fr = (m + M) a
fr = μ N
N- W = 0
N = (m + M) g
μ (m + M) g = (m + M) a
a = μ g
a = 0.30 9.8
a = 2.94 m / s²
We use kinematics to find the distance traveled, the final speed is zero
v² = v₀² - 2 a x
x = v₀² / 2 a
x = 0.667² / (2 2.94)
x = 0.0756 m