Complete Question
Q. Two go-carts, A and B, race each other around a 1.0km track. Go-cart A travels at a constant speed of 20m/s. Go-cart B accelerates uniformly from rest at a rate of 0.333m/s^2. Which go-cart wins the race and by how much time?
Answer:
Go-cart A is faster
Explanation:
From the question we are told that
The length of the track is 
The speed of A is 
The uniform acceleration of B is 
Generally the time taken by go-cart A is mathematically represented as
=> 
=> 
Generally from kinematic equation we can evaluate the time taken by go-cart B as

given that go-cart B starts from rest u = 0 m/s
So

=>
=>
Comparing
we see that
is smaller so go-cart A is faster
Complete Question
A certain refrigerator, operating between temperatures of -8.00°C and +23.2°C, can be approximated as a Carnot refrigerator.
What is the refrigerator's coefficient of performance? COP
(b) What If? What would be the coefficient of performance if the refrigerator (operating between the same temperatures) was instead used as a heat pump? COP
Answer:
a

b
Explanation:
From the question we are told that
The lower operation temperature of refrigerator is
The upper operation temperature of the refrigerator is 
Generally the refrigerators coefficient of performance is mathematically represented as

=> 
=> 
Generally if a refrigerator (operating between the same temperatures) was instead used as a heat pump , the coefficient of performance is mathematically represented as
=>
=>
Answer:
Angular acceleration = 23.68 rad / s²
Explanation:
Given that,
acceleration = 9m/s²
Therefore acceleration of string is 9m/s²
since string is constant in length
cylinder of radius 38.0 cm = 0.38m
Angular acceleration = a / r
Angular acceleration = 9 / 0.38
= 23.68 rad / s²
Angular acceleration = 23.68 rad / s²
(30, 5)
(10, 1)
change of y / change of x
= (30 - 10) / (5 - 1)
= 20 /4
= 5
Because they behave just like all the electromagnetic waves of the spectrum. Same equations, just shorter wavelengths and more energy.
Hope you get it :)