Answer:
37.545 m/s
Explanation:
f' = Actual frequency of horn = 269 Hz
f = Observed frequency of horn = 290 Hz
v = Speed of sound in air = 343 m/s
= Speed of second train = 13.7 m/s
= Speed of first train
From Doppler effect we have
The speed of the first train is 37.545 m/s
Answer: Radiation
Explanation:
There are three ways in which the thermal transfer occurs:
1. By Conduction, when the transmission is by the <u>direct contact</u>.
2. By Convection, heat transfer <u>in fluids </u>(like water or the air, for example).
3. By Radiation, by the <u>electromagnetic waves</u> (they can travel through any medium and in <u>vacumm</u>)
So, in the outter space is vacuum, this means the energy cannot be transmitted by convection, nor conduction. It must be transmitted by electromagnetic waves that are able to travel with or without a medium, and this is called radiation.
Velocity - <span><span>the speed of something in a given direction
Speed - </span></span><span>rapidity in moving, going, traveling, proceeding, or performing; swiftness; <span>celerity
Velocity is the speed in a certain direction, whereas speed is just the rate of fastness.
Does that make sense?
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Speed is v = d/t
Or speed is distance over time
So...
40min / 60min = 0.6667 or 2/3 --> Finding what proportion 40 minutes is to an hour or 60 minutes as we need the units of hours to match up
45km/h = d/0.6667h
d = (45)(0.667)
d = 30.0015 or 30km
