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Ksju [112]
3 years ago
7

If in 30 mins Alex runs to a store that is 4 km away, what is her average speed in km/h

Physics
1 answer:
masha68 [24]3 years ago
6 0
15 km 30 divided by 4 is 7.5 km in 30 min times that by 2 the answer is 15
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A series of evenly timed pulses create a wave that can be described as a _______<br><br> wave.
son4ous [18]

Answer:

Periodic

Explanation:

A periodic (or repetitive) wave has continuously repeating pattern with characteristics such as amplitude, wavelength and frequency. In a periodic wave, a series of pulses that are evenly timed would be created. In other words, the wave pattern in a periodic wave repeats at regular intervals.

An example of a periodic wave is the sound from the strings of a violin.`

8 0
3 years ago
Someone pls answer this with steps
Ivanshal [37]
No worry’s I am here to help
8 0
3 years ago
A wheel turns through 5.5 revolutions while being accelerated from rest at 20rpm/s.(a) What is the final angular speed ? (b) How
alina1380 [7]

Answer:

(a) The final angular speed is 12.05 rad/s

(b) The time taken to turn 5.5 revolutions is 5.74 s

Explanation:

Given;

number of revolutions, θ = 5.5 revolutions

acceleration of the wheel, α = 20 rpm/s

number of revolutions in radian is given as;

θ = 5.5 x 2π = 34.562 rad

angular acceleration in rad/s² is given as;

\alpha = \frac{20 \ rev}{min} *\frac{1}{s} *(\frac{2\pi \ rad}{1 \ rev } *\frac{1 \ min}{60 \ s}) \\\\\alpha = 2.1 \ rad/s^2

(a)

The final angular speed is given as;

\omega _f^2 = \omega_i ^2 + 2\alpha \theta\\\\\omega _f^2 = 0 +  2\alpha \theta\\\\\omega _f^2 =   2\alpha \theta\\\\\omega _f = \sqrt{2\alpha \theta}\\\\ \omega _f  = \sqrt{2(2.1) (34.562)}\\\\ \omega _f = 12.05 \ rad/s

(b) the time taken to turn 5.5 revolutions is given as

\omega _f = \omega _i + \alpha t\\\\12.05 = 0 + 2.1t\\\\t = \frac{12.05}{2.1} \\\\t = 5.74 \ s

3 0
3 years ago
The sound of a tuba is very low. Why?
vaieri [72.5K]

Answer:

When you blow into a tuba the air vibrates very slowly.​

Explanation:

Tuba is a buzz instrument ie sound is produced in it with the help of lip vibration . It is the lowest pitched musical instrument in the brass family .

Due to absence of resonance in it , it produces music of lowest pitch , So when one blows into it the air column of the instrument vibrates very slowly producing low pitched sound.

8 0
3 years ago
State the methods of nuclear fission waste disposal and the suitability of each method.
Alexeev081 [22]
<span>Most low-level radioactive waste (LLW) is typically sent to land-based disposal immediately following its packaging for long-term management. This means that for the majority (~90% by volume) of all of the waste types produced by nuclear technologies, a satisfactory disposal means has been developed and is being implemented around the world.
</span>

Radioactive wastes are stored so as to avoid any chance of radiation exposure to people, or any pollution.The radioactivity of the wastes decays with time, providing a strong incentive to store high-level waste for about 50 years before disposal.Disposal of low-level waste is straightforward and can be undertaken safely almost anywhere.Storage of used fuel is normally under water for at least five years and then often in dry storage.<span>Deep geological disposal is widely agreed to be the best solution for final disposal of the most radioactive waste produced.

</span>I suggest this site on this subject http://www.world-nuclear.org/information-library/nuclear-fuel-cycle/nuclear-wastes/storage-and-dispo...
5 0
4 years ago
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