Question

Two football players collide head-on in midair while chasing a pass. The first player has a 110 kg mass and an initial velocity of 4.20 m/s in the positive x direction, while the second player has a 135 kg mass and initial velocity of 3.40 m/s in the negative x direction. What is the x component of their velocity just after impact if they cling together? (Indicate the direction with the sign of your answer.)

Answer 1

Answer:

v = 0.012 m/s

Explanation:

This is a problem of momnetun, to solve it we must define a system that includes both players. In this case the forces during the crash are internal forces and the momentum is preserved

Initial

      p₀ = m₁ v₁₀ + m₂ v₂₀

Final

     $p_{f}$ = (m₁ + m₂) v

Because the two players are united

    p₀ = $p_{f}$

    m₁ v₁₀ + m₂ v₂₀ = = (m₁ + m₂) v

    v = (m₁ v₁₀ + m₂ v₂₀) / (m₁ + m₂)

let's calculate

    v = (110 4.20 - 135 3.40) / (110 + 135)

    v = 3/245

    v = 0.012 m/s

The positive sign indicates that they move to the right