Respuesta :
Answer:
a) Δp = -2.0 kgm / s,  b)  Δp = -4 kg m / s
Explanation:
In this exercise the change in moment of a ball is asked in two different cases
a) clay ball, in this case the ball sticks to the door and we have an inelastic collision where the final velocity of the ball is zero
     Δp = p_f - p₀
     Δp = 0 - m v₀
     Δp = - 0.100 20
     Δp = -2.0 kgm / s
b) in this case we have a bouncing ball, this is an elastic collision, as the gate is fixed it can be considered an object of infinite mass, therefore the final speed of the ball has the same modulus of the initial velocity, but address would count
     v_f = - v₀
    Δp = p_f -p₀
    Δp = m v_f - m v₀
    Δp = m (v_f -v₀)
    Δp = 0.100 (-20 - 20)
    Δp = -4 kg m / s
