The velocity is extraneous information. Frequency is the inverse of the period, thus the frequency of the wave is 1/3 Hz.
From information given, there are two forces in action, the vertical and the horizontal. We first need to calculate separately work done by these two forces, then determine the efficiency.
Work = Force × distance
work(a) → 600N × 2m = 1,200 Nm
work(b) → 300N × 5m = 1,500 Nm
Efficiency = work(a) / work (b) × 100
Efficiency = 1200 / 1500 × 100
Efficiency = 0.8 × 100
Efficiency = 80%
Therefore the efficiency of the ramp is 80%
Angle at which under water diver sees the sun from horizontal = 
Angle from normal direction = 90 - 57 = 
Refractive index of water = 1.33
Refractive index of water = 1
We have the equation
1.33 * sin
= 1 *sin 
= 
This angle is angle from normal, so angle seen by fisherman from horizontal = 90 - 46.42 = 
Vectorial form:
3.6 m east => 3i
6.0 north => 6 j
Final position = 3.6i + 6j
Magnitude = √[ (3.6)^2 + 6^2] = √[12.96 + 36] = √48.96 = 7.0 m
Direction => arc tan (6/3.6) = arc tan (1.67) = 59.0 °
Answer: the dog is at 7.0 m, 59.0° to the north of the east from the starting point.