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

=> 
=> 
Scott-Dannemiller, Koeninger, Briscoe, and Carter
Christopher-Briscoe, Dannemiller, and Koeninger
Dianne-Koeninger, Briscoe, and Carter
Kailee-Koeninger and Carter
Answer:
17.5 m/s²
1.90476 seconds
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity
s = Displacement
a = Acceleration
Force

Initial acceleration of the rocket is 17.5 m/s²

Time taken by the rocket to reach 120 km/h is 1.90476 seconds
Change in the velocity of a rocket is given by the Tsiolkovsky rocket equation

where,
= Initial mass of rocket with fuel
= Final mass of rocket without fuel
= Exhaust gas velocity
Hence, the change in velocity increases as the mass decreases which changes the acceleration
Answer:
The second one, the higher the hertz the higher the frequency we hear
Explanation:
The period of the pendulum is given by the following equation
T = 2π * sqrt (L/g)
Where g is the gravity (free fall acceleration)
L is the longitude of the pendulum
T is the period.
We find g.............> (T /2π)^2 = L/g
g = L/(T /2π)^2...........> g = 22.657 m/s^2