I’m almost sure it’s b , hope this helps on cripwalker
D.
gas>liq>solid
as density increases, speed decreases.
To calculate the acceleration of the skater on the rough ice, we use the equation

Here, u is initial speed when she hits the patch of ice and its value is 10 m/s and v is final speed when she left the patch of ice and its value is given 7.0 m/s and s is the width of patch of ice and its value is 5.0 m.
Substituting these values in above equation we get,
.
Thus, the acceleration of skater on the rough ice is 
194db is the loudest Sound wave
Answer: part a: 19.62m
part b: 19.62 m/s
part a: 2.83 secs
Explanation:If the air resistance is ignored then the swimmer experience free fall under gravity hence
u=0
a=9.81 m/s2
t=2 secs

s=h

Part b

Part c
now we have h=2*19.62=39.24
