Answer:

Explanation:
As we know that the formula of range is given as

now we know that
maximum value of the range of the projectile is given as

now we need to find such angles for which the range is half the maximum value
so we will have




Because the scientific method can go around in a circle as many times as neccisary to get the results you need
Answer:
a)
0.245 m/s
b)
0.904 m
Explanation:
a)
= speed of duck ahead of wave
= 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
=
- 
= 0.32 - 
= 0.245 m/s
b)
= speed of wave behind the duck
speed of wave behind the duck is given as
=
+ 
= 0.32 + 0.245
= 0.565 m/s
D = spacing between the crests
spacing between the crests is given as
D =
T
D = (0.565) (1.6)
D = 0.904 m