Answer
The average force exerted on the bird during the collision is $6.64~N$
Work Step by Step
We can find the change in velocity:
$\Delta v = v_f-v_0 = (4.1~m/s)-(-11.1~m/s) = 15.2~m/s$
We can use the change in velocity to find the change in the bird's momentum:
$\Delta p = m~\Delta v$
$\Delta p = (0.031~kg)(15.2~m/s)$
$\Delta p = 0.4712~kg~m/s$
The impulse exerted on the bird is equal to the bird's change in momentum:
$F~t = \Delta p$
$F = \frac{\Delta p}{t}$
$F = \frac{0.4712~kg~m/s}{0.071~s}$
$F = 6.64~N$
The average force exerted on the bird during the collision is $6.64~N$.
