Eduprobe
Question:
A body of mass m_1 moving with an unknown velocity of v_1, undergoes a collinear collision with a body of mass m_2 moving with a velocity v_2. After collision, m_1 and m_2 move with velocities of v_3 and v_4, respectively. If m_2 = 0.5 m_1 and v_3 = 0.5 v_1, then v_1 is :
v4−v2
v4−v22
v4+v2
v4−v24
Solution:
Correct option is C. v4+v2
Applying linear momentum conservation
m1v1i^ + m2v2i^ = m1v3i^ + m2v4i^
m1v1 + 0.5m1v2 = m1(0.5v1) + 0.5m1v4
0.5m1v1 = 0.5m1(v4 - v2)
v1 = v4 + v2