D, it is considered unethical today
(1 parsec) is the distance at which an object has a parallax of 1 arcsecond. The distance is about 3.26 light years.
Another way to understand it is: The distance from which the Earth's orbit appears 1 arcsecond across.
For a parallax angle of 1/2 arcsecond, the distance is <em>2 parsecs </em>(about 6.52 light years).
1 arcsecond is 1/3600 of a degree, 0.00028 degree.
Complete Question
The complete question is shown on the first uploaded image
Answer:
The velocity is
in positive x -direction
The speed is 
Explanation:
From the question we are told that
The distance from the house to truck is D = 20 m
The distance traveled back to retrieve wind-blown hat is d = 15
The distance from the wind-blown hat position too the truck is k = 20 m
The total time taken is t = 75 s
Generally when calculating the displacement the Justin's backward movement to collect his wind - blown hat is taken as negative
Generally Justin's displacement is mathematically represented as

=> 
Generally the average velocity is mathematically represented as

=> 
=>
Generally the distance covered by Justin is mathematically represented as

=> 
=> 
Generally Justin's average speed over a 75 s period is mathematically represented as

=> 
=> 