Answer:
a. 
b. Δ
c. 
Explanation:
a).
Momentum conserved





b).
Δ


Δ
c).


d).
All of which has been lost as mechanical energy, and is now thermal energy warmer football players, noise a loud crunch for example.
Answer:
a. It became deeper by a factor of 3.
Explanation:
What we have is water flowing down a river with constant width. The water slows from speed v to v3 over a shirt distance
Using the equation of continuity
A1V1 = A2V2 ----1
A1 is the area of rectangle
V1 is the velocity of water
Area of rectangle = length x width
We rewrite equation 1 as
λ1w1v1 = λ2w2v2
We have w1 = w2
λ1v1 = λ2v2
λ1*v1 = λ2*v/3
λ1 = λ2/3
So it becomes deeper by a factor of 3