Answer:
In terms of distance, average speed is 20 km/h
In terms of displacement, average speed is 0 km/h.
Explanation:
Total distance:

Total time is 3.0 hours
but:

In terms of distance.
substitute:


In terms of displacement:

Complete question:
Part A:) The fictional rocket ship Adventure is measured to be 50 m long by the ship's captain inside the rocket.When the rocket moves past a space dock at 0.5c , space-dock personnel measure the rocket ship to be 43.3 m long. The rocket ship Adventure travels to a star many light-years away, then turns around and returns at the same speed. When it returns to the space dock, who would have aged less: the space-dock personnel or ship's captain?
Part B: What is the momentum of a proton traveling at 0.62 c ?
Answer
a)Who would have aged less=The Captain would have aged less
b) 
Explanation:
From the question we are told that
Length measured by captain 
Speed of rocket past tje space dock 
Length measured by space-dock personnel 
a)
Generally time moves slower when moving at speed of light, due to time dilation or variation.
Who would have aged less=The Captain would have aged less
b)
Generally the equation for Relativistic Momentum is mathematically given as



Yes, you can chemically change or alter DNA
Then the tangent of angle-Θ is (Ay / Ax).