Water as it's the highest specific heat capacity
Hope this helps x
Answer:
9 meters
Explanation:
Given:
Mass of Avi is, 
Spring constant is, 
Compression in the spring is, 
Let the maximum height reached be 'h' m.
Now, as the spring is compressed, there is elastic potential energy stored in the spring. This elastic potential energy is transferred to Avi in the form of gravitational potential energy.
So, by law of conservation of energy, decrease in elastic potential energy is equal to increase in gravitational potential energy.
Decrease in elastic potential energy is given as:

Now, increase in gravitational potential energy is given as:

Now, increase in gravitational potential energy is equal decrease in elastic potential energy. Therefore,

Therefore, Avi will reach a maximum height of 9 meters.
1) 3 miles/Hour
The speed is defined as the distance covered divided by the time taken:

where
d = 1.5 mi is the distance
t = 0.5 h is the time taken
Substituting,

2) 1.34 m/s south
Velocity, instead, is a vector, so it has both a magnitude and a direction. We have:
is the displacement in meters
is the time taken in seconds
Substituting,

And the direction of the velocity is the same as the displacement, so it is south.