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

=> 
=> 
C. A 1200kg car is going 15m/s
She does work from the moment she touches the book until she lets it go. Work is anything that requires energy. Therefore, she is working as she picks up the book, carries it, and when she is lifting it onto the shelf.
Answer:
P = 23.32 W
Explanation:
In series
equivalent Resistance
R(eq)=R+R=2R
In parallel equivalent resistance
R(eq) = R*R/(R+R) =R/2
since.
power
P=V² / R
in series
⇒V = √(P*R)
=√(5.83*2R
)
=√(11.66R)
in parallel
P = V² / R(eq)
=(√(11.66R)²) / (R/2)
P=11.66 * R * 2/R
P = 23.32 W