Physics, 18.08.2019 10:20 jacksonshalika

Arailway train 50 m long passes over a bridge 250 m long at the rate of 12 km/h. how long will it take completely pass over the bridge?

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From the instant when the nose of the locomotive reaches the beginning of the
bridge, it has to travel the whole 250m to get to the other end of the bridge, and
then it has to travel another 50m to get the rest of the train off the bridge. So it
has to travel 300m to get everything it's pulling across the bridge.

Time = distance/speed = 300m / (12,000 m/hr) = 0.025 hour = 1 minute 30 sec

Answer from: ellamai16

Pretty slow that train ;)

t=s/v
v=12 km/h=10/3 m/s
s=250+50=300 m

t=300/(10/3)
t=300*3/10
t=30*3
t=90 s=1.5 min

Answer from: Quest

most voltage drop calculators want the distance between the source and destination. then internally, they double it so both the source and return wires are calculated. but you need to know which distance the calculator uses so you're not half of what you should be or double what you should be.

most circuit breakers will not take a #6 directly, so the electrician will have to splice on a smaller pigtail. you also have to upsize the grounding wire when you upsized the ungrounded (hot) wire (see note in 250.122). this will preclude using most cable assemblies, as a cable with #6 copper will most likely only have a #10 grounding conductor. you need a #6 grounding conductor if the circuit is 20a. a #8 cable is no better, as it will have a #10 grounding conductor too. but most 20a breakers will take a #8 directly.

in your related post, you didn't say what type of load this is. if it is a light or heater, voltage drop won't be a big issue. if this is a motor, the current needs are huge at startup and the voltage drop can pose a problem. if this is a motor, knowing if the motor is under much load during startup will answer the voltage drop effect (a saw is easier to start than a compressor).

Answer from: Quest

i dont know but

explanation:

whoever your teacher is, deserves a raise for using pokemon as an example

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Arailway train 50 m long passes over a bridge 250 m long at the rate of 12 km/h. how long will it ta...