Answer:
a)
0.245 m/s
b)
0.904 m
Explanation:
a)
[tex]v_{d}[/tex] = speed of duck ahead of wave
[tex]v_{s}[/tex] = speed of surface wave = 0.32 m/s
T = time for paddling = 1.6 s
d = spacing between the waves = 0.12 m
speed of duck ahead of wave is given as
[tex]v_{d}[/tex] = [tex]v_{s}[/tex] - [tex]\frac{d}{T}[/tex]
[tex]v_{d}[/tex] = 0.32 - [tex]\frac{0.12}{1.6}[/tex]
[tex]v_{d}[/tex] = 0.245 m/s
b)
[tex]v_{w}[/tex] = speed of wave behind the duck
speed of wave behind the duck is given as
[tex]v_{w}[/tex] = [tex]v_{s}[/tex] + [tex]v_{d}[/tex]
[tex]v_{w}[/tex] = 0.32 + 0.245
[tex]v_{w}[/tex] = 0.565 m/s
D = spacing between the crests
spacing between the crests is given as
D = [tex]v_{w}[/tex] T
D = (0.565) (1.6)
D = 0.904 m