Question

Two particles of equal mass mo, moving with equal speeds v_o (A) along paths inclined at 60° to the x-axis as shown, collide and stick together. Their velocity after the collision has magnitude

(A) v₀/4

(B) v₀/2

(C) √2v₀/2

(D) √3v₀/2

(E) v₀.

Answer 1

Correct option  (B) V₀/2

2D collision. The y momentums are equal and opposite and will cancel out leaving only the x momentums which are also equal and will add together to give a total momentum equal to twice the x component momentum before hand. p_before = p_after 2m_ov_ocos60 = (2m_o)v_f .