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o-na [289]
3 years ago
7

In old times, before there were train signals, people who worked on the railroad would often put their ear down to the train tra

ck to listen for an oncoming train. Why would this result in hearing the train further off than just listening for the train through the air? Question 3 options: Sound travels slower in air because there are often trees and other items blocking the sound. People did not do this because sound travels faster through less dense material, like air, rather than more dense materiel, like train tracks. Sound travels slower, but louder through solid material because it is more dense, so the train could be heard better this way. Sound waves travel faster in more dense material, and the more dense the material the faster the sound is.
Physics
1 answer:
elena55 [62]3 years ago
8 0
The answer is the second option or B.
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How many seconds of space should you keep between you if you're driving a 100 foot truck 30 mph?
Marrrta [24]

Answer:

<em> The space in seconds that will be kept = 2.27 seconds</em>

Explanation:

S = d/t..................... Equation 1

making t the subject of formula in the equation above,

t = d/S.................... Equation 2

Where S = speed, d = distance, t = time.

<em>Conversion: (i)if 1 mph = 0.44704 m/s,</em>

<em>                 then, 30 mph = 30×0.44704    </em>

<em>                = 13.41 m/s</em>

<em>               (ii) If 1 foot = 0.3048 m</em>

<em>            then, 100 foot = 30.48 m.</em>

<em>Given: S = 30 mph = 13.41 m/s, d = 100 foot = 30.48 m</em>

<em>Substituting these values into equation 2</em>

<em>t = 30.48/13.41</em>

<em>t = 2.27 seconds.</em>

<em>Therefore the space in seconds that will be kept = 2.27 seconds</em>

7 0
4 years ago
A 30.0 kg box hangs from a rope. What is the tension (in N) in the rope if the box has an initial velocity of 2.0 m/s and is slo
hjlf

Answer:

360 N

Explanation:

m = 30kg    u = 2 m/s     a = -2m/s/s

Since the object has an initial velocity of 2 m/s and acceleration of -2 m/s/s

the object will come to rest in 1 second but the force applied in that one second can be calculated by:

F = ma

F = 30 * -2

F = -60 N (the negative sign tells us that the force is acting downwards)

Now, calculating the force applied on the box due to gravity

letting g = -10m/s/s

F = ma

F = 30 * -10

F = -300 N (the negative sign tells us that the force is acting downwards)

Now, calculating the total downward force:

-300 + (-60) = -360 N

<em></em>

<em>Hence, a downward force of 360 N is being applied on the box and since the box did not disconnect from the rope, the rope applied the same amount of force in the opposite direction</em>

Therefore tension on the force = <u>360 N</u>

5 0
4 years ago
State examples of a transverse wave. ​
laiz [17]

ripples on the surface of water.

vibrations in a guitar string.

a Mexican wave in a sports stadium.

electromagnetic waves – eg light waves, microwaves, radio waves.

seismic S-waves.

6 0
3 years ago
Read 2 more answers
Which restricted basin has the coolest temperatures?
sattari [20]

Hudson Bay is the  restricted basin that has the coolest temperatures

Hudson Bay is a restricted basin which  remains frozen or is dominated by ice over the summer solstice and through- out much of the high-sun season. This basin experiences a harsh continental climate.

The average annual temperature in almost the entire bay is around 0 °C (32 °F) or below. In the extreme northeast, winter temperatures average as low as −29 °C or −20.2 °F. The region of this basin has very low year-round average temperatures.

This basin starts freezing up by early November, and the northern part of the basin is typically entirely iced over by the end of the month.

correct answer is Hudson bay

learn more about basin :

brainly.com/question/11871406?referrer=searchResults

#SPJ4

3 0
2 years ago
It is important for physicians to be _____ patient use of alternative therapies.
V125BC [204]
It is important for physicians to be Respectful of patient use of alternative therapies

Alternative therapies usually have not gain a scientific approval from the scientific community, but there are some therapies that show positive results even though it is still has not proved by studies or researches. So it's important for physicians to be respectful if the patient choose to do it
3 0
3 years ago
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