Answer:
choosing a material that will show warning before it fails
Explanation:
According to my research on different architectural engineering techniques, I can say that based on the information provided within the question this is an example of choosing a material that will show warning before it fails. By choosing aluminum he can detect certain failures a long time before it actually happens since aluminum shows signs of wear and tear and doesn't just break immediately.
I hope this answered your question. If you have any more questions feel free to ask away at Brainly.
Answer:
To calculate anything - speed, acceleration, all that - we need <em>data</em>. The more data we have, and the more accurate that data is, the more accurate our calculations will be. To collect that data, we need to <em>measure </em>it somehow. To measure anything, we need tools and a method. Speed is a measure of distance over time, so we'll need tools for measuring <em>time </em>and <em>distance</em>, and a method for measuring each.
Conveniently, the lamp posts in this problem are equally spaced, and we can treat that spacing as our measuring stick. To measure speed, we'll need to bring time in somehow too, and that's where the stopwatch comes in. A good method might go like this:
- Press start on the stopwatch right as you pass a lamp post
- Each time you pass another lamp post, press the lap button on the stopwatch
- Press stop after however many lamp posts you'd like, making sure to hit stop right as you pass the last lamp post
- Record your data
- Calculate the time intervals for passing each lamp post using the lap data
- Calculate the average of all those invervals and divide by 40 m - this will give you an approximate average speed
Of course, you'll never find an *exact* amount, but the more data points you have, the better your approximation will become.
A sound is first produced by making something<span> vibrate</span><span>. The sound then travels through a </span><span> medium</span><span> to reach the ears, which are the parts of the body that allow for sounds to be heard.
Vibrate and Medium are the correct answers
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Answer:
The minimum riding speed relative to the whistle (stationary) to be able to hear the sound at 21.0 kHz frequency is 15.7 m/s
Explanation:
The Doppler shift equation is given as follows;

Where:
f' = Required observed frequency = 20.0 kHz
f = Real frequency = 21.0 kHz
v = Sound wave velocity = 330 m/s
= Observer velocity = X m/s
= Source velocity = 0 m/s (Assuming the source is stationary)
Which gives;

330 -
= (20/21)*330
= 330 - (20/21)*330 = 15.7 m/s
The minimum riding speed relative to the whistle (stationary) to be able to hear the sound at 21.0 kHz frequency = 15.7 m/s.
Answer: When the electric field due to one is a maximum, the electric field due to the other is also a maximum, and this relation is maintained as time passes. They alternatively reinforce and cancel each other.
Explanation:
In a wave, the phase, is an arbitrary time reference, used to locate a given point of the wave in time, within a cycle.
Two waves can travel at the same speed, or even have the same wavelength, but this is not enough to be sure that at a given point in time, both waves will be in their maximum, as it only can be determined from the phase of the waves.
So, only when the waves reach at the same point in time at the same amplitude, we can say that they arrive in phase, in a constructive interference.