Answer:
13 km/h
Explanation:
Average speed = distance/time
Let the total distance and total time taken for the whole trip be d km and t hours respectively
Average speed for the whole trip = 82 km/h
d = 82t
The distance covered in the first half = d1/2
Time taken = t/2
Average speed = 69 km/h
69 = d1/2 ÷ t/2
d1 = 69t
The distance covered in the second half = d2/2
Time taken = t/2
Let the average sly for the see half be A
A = d2/2 ÷ t/2
d2 = At
d = d1 + d2
82t = 69t + At
At = 82t - 69t
At = 13t
A = 13t/t = 13 km/h
Answer:
Joule ;)
Explanation:
In the case of work (and also energy), the standard metric unit is the Joule (abbreviated J). One Joule is equivalent to one Newton of force causing a displacement of one meter. In other words, The Joule is the unit of work.
Hope this helps!
Answer:
The value is 
Explanation:
From the question we are told that
The work input is
The heat delivered is 
The value of A is A = 14
The value of B is B = 72
Generally the efficiency of the heat engine is mathematically represented as

Here
is the total out energy produce by the heat engine and this is mathematically represented as

=> 
=> 
So

=> 
=> 
=> 
Stars are huge celestial bodies made mostly of hydrogen and helium that produce light and heat from the churning nuclear forges inside their cores. Aside from our sun, the dots of light we see in the sky are all light-years from Earth. They are the building blocks of galaxies, of which there are billions in the universe. It’s impossible to know how many stars exist, but astronomers estimate that in our Milky Way galaxy alone, there are about 300 billion.
Work is done when spring is extended or compressed. Elastic potential energy is stored in the spring. Provided inelastic deformation has not happened, the work done is equal to the elastic potential energy stored.