Answer:
Explanation:
Given
mass of boy [tex]m_b=70.9\ kg[/tex]
mass of girl [tex]m_g=43.2\ kg[/tex]
speed of girl after push [tex]v_g=4.64\ m/s[/tex]
Suppose speed of boy after push is [tex]v_b[/tex]
initially momentum of system is zero so final momentum is also zero because momentum is conserved
[tex]P_i=P=f[/tex]
[tex]0=m_b\cdot v_b+m_g\cdot v_g[/tex]
[tex]v_b=-\frac{m_g}{m_b}\times v_g[/tex]
[tex]v_b=-\frac{43.2}{70.9}\times 4.64[/tex]
[tex]v_b=-2.82\ m/s[/tex]
i.e. velocity of boy is 2.82 m/s towards west
The final velocity of the boy is 2.83 m/s westward.
The final velocity of the boy is determined by applying the principle of conservation of linear momentum as shown below;
Sum of initial momentum = Sum of final momentum
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂
70.9(0) - 43.2(0) = 70.9(v₁) + 43.2(4.64)
0 = 70.9v₁ + 200.448
-70.9v₁ = 200.448
-v₁ = 200.448/70.9
v₁ = -2.83 m/s
Thus, the final velocity of the boy is 2.83 m/s westward.
Learn more about conservation of linear momentum here: https://brainly.com/question/7538238
