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
Crank
3 years ago
6

A subway train starts from rest at a station and accelerates uniformly at 1.8m/s^2 for 15 sec. then it runs at a constant speed

for the next 35 sec. before decelerating at 2.0m/s^2 until it comes to rest at the next station. FIND THE DISTANCE between the stations and the AVERAGE SPEED of the train.
(please show step by step and the formula that is used. Thank you!)

Physics
1 answer:
miv72 [106K]3 years ago
8 0
This looks so scary just because there are so many parts to it.
Take them one at a time:

<u>First piece:</u>
From rest, accelerates 1.8 m/s² for 15 sec.
Speed at the end of the 15 sec = 1.8 x 15 = 27 m/s
Distance covered = (average speed) x (time) = (13.5) x (15) = 202.5 meters

<u>Middle piece:</u>
Starts this piece at 27 m/s.
Runs at constant speed for 35 sec.
Covers (27 x 35) = 945 meters
Finishes this piece (15 + 35) = 50 seconds after leaving the first station
Finishes this piece (202.5 + 945) = 1147.5 meters from the first station.

<u>Last piece:</u>
Starts this piece 50 seconds after leaving the first station,
         1147.5 meters from it, still moving at 27 m/s.
Decelerates at 2.0 m/s² .
--> It takes 27/2.0 = 13.5 seconds to come to a stop.
--> Distance covered during this piece = (average speed) x (time)
           = (13.5 m/s) x (13.5 sec) = 182.25 meters
Finishes this piece (50 + 13.5) = 63.5 seconds after leaving the first station
Finishes this piece (1147.5 + 182.25) = 1,329.75 m from the first station  

Distance between the stations (along the track) = 1,329.75 meters.

Average speed = (total distance) / (total time) = 1,329.75 / 63.5 = 20.941 m/s.

I sure hope I didn't make any stupid arithmetic blunders here,
because I really don't feel like going back and checking it.
Let me know, and I'll fix them.


You might be interested in
Tornadoes are most frequent from _____. April to June October to December January to March July to August
jenyasd209 [6]

Answer:

April to June

Explanation:

Not really an explanation, I just know it.

8 0
3 years ago
Technician A says that the manual valve position is controlled by the shift lever. Technician B says that the manual valve posit
LenaWriter [7]

Options: A. Tech A. B. Tech B. C. Tech And B. C. None of the above.

Answer:Tech A and B

Explanation:A shift lever is the lever installed on the steering column or floor of a vehicle which allows the driver to shift gears or change gears, the manual valve position is controlled by shift lever as the shift lever moves the manual valve position changes. The

Ball Plungers are self-contained ball-and-spring devices,used in rolling and detent applications, they are used to position the manual valve in a vehicle.

8 0
3 years ago
Which geologic feature would most likely be represented by contour lines drawn far apart from one another?
Anna [14]
It would most definitely not be a hill or a cliff. I believe it would be a plain.
5 0
2 years ago
Ahmed kept a balloon from his birthday for several days until it began to deflate and slowly sink to the ground. He wondered how
goldfiish [28.3K]
<span>He should study the chapter about laws to get a better understanding about the laws that govern physical objects</span>
8 0
3 years ago
Read 2 more answers
Two 5 kg potted cacti, one in a black pot and one in a blue pot, slide down a sagging shelf in the same direction with
svp [43]

Answer:

Answers A and D are the correct solution.

Explanation:

Both pots have the same mass and the same velocity vector.

the only difference between A and D is the selection of the reference frame positive direction.

5 0
2 years ago
Other questions:
  • Cecily is inflating one of her bicycle tyres with the pump below. When she pushes the plunger down, does the volume of the gas i
    14·1 answer
  • A particle's position along the x-axis is described by. x(t)= At+Bt^2where t is In seconds: x is in meters: and the constants A
    11·1 answer
  • Consider the waves on a vibrating guitar string and the sound waves the guitar produces in the surrounding air. The string waves
    7·1 answer
  • Three remote control cars are identical size and weight. The motors installed in the three cars are 100 watts, 150 watts and 200
    7·1 answer
  • If A bar + B bar = C bar and magnitude of A bar + magnitude of B bar = magnitude of C bar. Then the angle between A bar and B ba
    6·1 answer
  • An ambulance is driving towards the hospital at a velocity 108 km/h and emitting a steady 798-Hz sound from its siren. The sound
    7·1 answer
  • A tennis ball is released from a height of 2.0 m above the floor, and then bounces three times. With each bounce, dissipative fo
    7·2 answers
  • How many atoms are present in 2 moles of chromium?
    6·1 answer
  • If a star were located exactly at each celestial pole, the corrected altitude of the star would equal __________.
    7·1 answer
  • Given that the wavelengths of visible light range from 400 nm to 700 nm, what is the highest frequency of visible light? (ccc =
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!