1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
saveliy_v [14]
3 years ago
10

A train travels 81 kilometers in 2 hours and then 90 kilometers in two hours. wat is the average speed

Physics
1 answer:
oee [108]3 years ago
5 0
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) | |
You might be interested in
A battery has an electric potential of 1.5V and transfers 10.0 C between the two terminals. How much work was done?
bogdanovich [222]

Answer:

15 Joules

Explanation:

work = charge x potential difference

= 10 x 1.5

= 15

8 0
3 years ago
The graph shows the amplitude of a passing wave over time in seconds (s). What is the approximate frequency of the wave shown?
belka [17]

Answer:

B) 0.3Hz

Explanation:

I just took the test i hope i helped and i hope you pass the test

7 0
3 years ago
Read 2 more answers
a typical cmall flashlight contains two batteries each having na emf of 2.0 v connected in series with a bulb havin ga resistanc
Helen [10]

Answer:

P = 0.25 W

Explanation:

Given that,

The emf of the battry, E = 2 V

The resistance of a bulb, R = 16 ohms

We need to find the power delivered to the bulb. We know that, the formula for the power delivered is given by :

P=\dfrac{V^2}{R}\\\\P=\dfrac{2^2}{16}\\\\=0.25\ W

So, 0.25 W power is delivered to the bulb.

5 0
3 years ago
Which is NOT one of the four principals of Dalton’s atomic theory?
Gre4nikov [31]

Answer:

Your answer would be letter <em><u>B</u></em><em><u>.</u></em><em><u> </u></em><em><u>Electrons</u></em><em><u> </u></em><em><u>orbit</u></em><em><u> </u></em><em><u>the</u></em><em><u> </u></em><em><u>nucleus</u></em><em><u> </u></em><em><u>in</u></em><em><u> </u></em><em><u>energy</u></em><em><u> </u></em><em><u>level</u></em><em><u>.</u></em>

Explanation:

Hope it helps..

Just correct me if I'm wrong, okay?

But ur welcome!!

(;ŏ﹏ŏ)(◕ᴗ◕✿)

8 0
2 years ago
Read 2 more answers
The product side of a chemical reaction is shown. → 7Ti2(SO4)3
Alex_Xolod [135]
The answer is the fourth choice because there are 7 represents in a coefficient.

7 0
3 years ago
Read 2 more answers
Other questions:
  • Describe Newton's First Law of motion. Provide an example to support your explanation. (4 points
    15·2 answers
  • A light platform is suspended from the ceiling by a spring. A student with a mass of 90 kg climbs onto the platform. When it sto
    11·1 answer
  • You have a pulley 10.4 cm in diameter and with a mass of 2.3 kg. You get to wondering whether the pulley is uniform. That is, is
    7·1 answer
  • A car of mass 500kg travelling at 60m/s has it speed reduced to 40m/s by a constant breaking force over a distance of 200m. find
    10·1 answer
  • A magnetically soft material is placed in a strong magnetic field. What is the most likely outcome?
    16·2 answers
  • I need help with two more Physics problems​
    7·2 answers
  • a fast humvee drove from desert a to desert b. for the 12 hours, it travelled at an speed of 185 km/h. for the next 13 hours, it
    15·1 answer
  • Determine the force of gravitational attraction between the Earth and the moon. Their masses are 5.98 x 1024 kg and 7.26 x 1022
    7·1 answer
  • A racing car has a mass of 1525kg. What is its kinetic energy if it has a speed of 108km/h
    7·1 answer
  • A pressure sensor was used to measure the unsteady pressure in a cylinder. The sensor output was acquired for 15 seconds at a ra
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!