Answer:from 0.75 to 1.25 hours
Explanation:
If the line goes straight, it means that time is going by but they're not moving.
I'm assuming your question refers to the train travels 81 km in 2 hours, as in that's the total distance covered versus the speed for those 2 hours, whereas the 90 km in 2 hours the second time around is the total distance not speed I would assume.
Now... if it was going 81 km for the first 2 hours and 90 km for the second 2 hours then the average speed would be the mean of these numbers, with that being 85.5 km. Though, I doubt that's your question.
With that said, 81 km covered by 2 hours and 90 km covered by 2 more hours. To acquire the km an hour average, we'll have to divide the distance by how many hours it traveled:
81 / 2 = 40.5
90 / 2 = 45
Meaning the train was going 40.5 km an hour for the first 2 hours and 45 km an hour for the second 2 hours. Now, to find the mean:
40.5 + 45 = 85.5 / 2 = 42.75
In-case you were wondering, the mean is the sum of all the numbers in a set, divided by the total amount of numbers in that set, take for instance:
3, 5, 9, 2, 1, 5. -> There are 6 numbers in this set.
3 + 5 + 9 + 2 + 1 + 5 = 25 -> 25 is the sum of these numbers.
25 / 6 = 4.2 (estimated) -> 4.2 is roughly the mean or average between the original set.
Anyhow, with that aside the average speed between this I would believe would be 42.75 km an hour. I hope that helps, have a great rest of your day! ^ ^
| | Ghostgate (Alter) | |
Answer:
The wavelength is
Explanation:
From the question we are told that
The energy band gap is
Generally the wavelength is mathematically evaluated as
Where h is the Plank constant with a value
c is the speed of light with constant value of
substituting values
<h2>
Answer: The volume will triple (increase by a factor of three).</h2>
Explanation:
The expression for an Ideal Gas is:
(1)
Where:
is the pressure of the gas
is the volume of the gas
the number of moles of gas
is the gas constant
is the absolute temperature of the gas
Finding :
(2)
If we are told the the amount of gas and pressure remain constant, but we increase the temperature by a factor of three; we will have to rewrite (2) with the new temperature :
(3)
(4)
Now, if we compare (2) with (4), it is clearly noticeable the volume of the gas has increased by a factor of 3.
The answers are A and D.
Engine oil reacts with rubber, changing its properties and causing it to expand. This will compromise rubber seals in the brake system and lead to a failure.