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) | |
The centripetal force on the ball is 140.9 N; option A
<h3>What is the centripetal force on the ball?</h3>
The centripetal force on the ball is given by the formula below:
where;
- m is mass
- v is linear velocity
- r is radius
The linear velocity, v = wr
v = 5 * 2π/4.4 * 1.4 = 9.93 m/s
F = 10² * 2/1.4 = 140.9 N
In conclusion, the centripetal force is derived from the mass, velocity and radius of the path.
Learn more about centripetal force at: brainly.com/question/20905151
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Answer:
Explanation:
We have the following relation between power, P and intensity, I
= 
= 
We also have the following relationship between electric field and electromagnetic radiation thus
Hence 
substituting the values of I, c and e, we have
Well if the ship was in space their shouldn’t be a loud bang. Because you can’t hear anything in space
