Where does most of the energy we use at home/our cars come from?

Your friends sit in a sled in the snow. If you apply a force pf 75 N to them, they have an acceleration of 0.9 m/s ^ 2. What is

Elza [17]

Answer:

Mass of the sled in the snow 83.33 kg.

<u>Explanation</u>:

Given that,

Force applied to move the sled in the snow (F) = 75N

$\text { Acceleration }(a)=0.9 \mathrm{m} / \mathrm{s}^{2}$

We know that

Newton's second law of motion is

$\text { Force }=\text { mass } \times \text { acceleration }$

F = ma (Or "force" is equal to "mass" times "acceleration".)

So if we move this around we can isolate mass and get mass

$\text { Mass }=\frac{\text { force }}{\text { accelearation }}$

$\mathrm{M}=\frac{75}{0.9}$

M = 83.33 kg

Mass of the sled in the snow <u>83.33 kg.</u>

3 0

3 years ago

When sound travels through air, the particles _____. a. vibrate along the direction the wave travels b. vibrate but not in any f

Mandarinka [93]

Vibrate along the direction the wave travels

8 0

3 years ago

When did humans learn that the earth is not the center of the universe?

Vinvika [58]

Answer:

When did humans learn that the Earth is not the center of the universe?

Answer

1

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4 Answers

Asked in 3 Spaces

Science - Next Generation

Alexander Somm

, Consultant, Investor Relations at Novelpharm AG (2015-present)

Answered Oct 16

What, it isn’t?!

Sorry, I had to.

As far as I have read and understood, the Sumerians and later the Babylonians both had astronomical calendars that already differentiated planets and stars. Earth was not the center to them, the Sun likely was. That was around 2,200 - 1,600 BC.

After that, Greek philosopher Aristarchus of Samos (310 - 230 BC) was the first (recorded) to have believed the solar system was organized around the Sun, rather than the Earth. His heliocentric model was unpopular during Aristarchus’ lifetime, although it would inspire astronomers centuries later, such as Copernicus and Galileo.

Now, there are numerous archeological findings (cave paintings) and studies, that all suggest an understanding of complex astronomy in prehistoric times dating back as far as 40,000 years. This also explains how early, prehistoric migrants may have navigated the seas.

Explanation:

hope it helps

have a good day

4 0

2 years ago

A pipe that is open at both ends has a fundamental frequency of 320 Hz when the speed of sound in air is 331 m/s.

fenix001 [56]

Question

What is the length of the pipe?

Answer:

(a) 0.52m

(b) f2=640 Hz and f3=960 Hz

(c) 352.9 Hz

Explanation:

For an open pipe, the velocity is given by

$v=\frac {2Lf}{n}$

Making L the subject then

$L=\frac {nV}{2f}$

Where f is the frequency, L is the length, n is harmonic number, v is velocity

Substituting 1 for n, 320 Hz for f and 331 m/s for v then

$L=\frac {1*331}{2*320}=0.5171875\approx 0.52m$

(b)

The next two harmonics is given by

f2=2fi

f3=3fi

f2=3*320=640 Hz

f3=3*320=960 Hz

Alternatively, $f2=2\times \frac {v}{2L}$ and $f3=3\times \frac {v}{2L}$

$f2=2\times \frac {331}{2*0.52}=636.5 Hz\\f3=3\times \frac {331}{2*0.52}=954.8 Hz$

(c)

When v=367 m/s then

$f1= \frac {v}{2L}\\f1= \frac {367}{2*0.52}=352.9 Hz$

5 0

3 years ago

What is the definition of physical change

jeka94

They are used to separate mixtures into their component compounds but can no usually be used to deprecate compounds into chemical elements or simpler compounds

7 0

3 years ago