Answer:
(a) the mass of the second body is 1.2 kg
(b) the speed of the two-body center of mass 2.5 m/s
Explanation:
Given;
mass of the body, m₁ = 2 kg
let the mass of the second body = m₂
let the initial speed of the first body, = u₁ = 4 m/s
then, the final speed of the first body, v₁= ¹/₄u₁ = 0.25u₁
initial speed of the second body, u₂ = 0
let the final speed of the second body = v₂
Apply principle of conservation of linear momentum to determine the mass of the second body;
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂
2u₁ + 0(m₂) = 2(0.25u₁) + m₂v₂
2u₁ = 0.5u₁ + m₂v₂
1.5(4) = m₂v₂
6 = m₂v₂
Apply one-directional velocity
u₁ + v₁ = u₂ + v₂
u₁ + (0.25u₁) = 0 + v₂
1.25u₁ = v₂
1.25(4) = v₂
5 = v₂
Then, the mass of the second body is calculated as;
m₂v₂ = 6
5m₂ = 6
m₂ = 6/5
m₂ = 1.2 kg
(b) the speed of the two-body center of mass after collision;
[tex]V_c_m = \frac{m_1v_1 + m_2v_2}{m_1 + m_2} \\\\V_c_m = \frac{2(0.25\times 4) \ + \ 1.2(5)}{2\ + \ 1.2} \\\\V_c_m = 2. 5 \ m/s[/tex]
