Yes it would get colder because people help people learn through experiences with no one to help teach the world would be a cold lifeless place.
Answer:
true
Explanation:
it is concave when it diverging
Answer:
It depends on the size and density but No.
Explanation:
Answer:
refractive index for water,glass,diamond are 0.752m, 0.667m, 0.413m respectively
Explanation:
refractive index (n) = 
velocity =
The time for travel is kept constant for all mediums.
refractive index (n) = 
distance in medium = 

For water, n= 1.33


For glass, n=1.5


For diamond, n= 2.42


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

=> 
=> 