Can someone help me please

Sound travels through water at speed of "1.43" km/s.how far does sound travel in 1000 seconds?

artcher [175]

Answer:

1.43x1000= 1430km

Explanation:

if it travels 1.43 km in 1 sec in 1000 it travels x1000 which is 1430

6 0

3 years ago

A car traveled at an average velocity of 97 km/hr. If it traveled for 4 hrs, how far did the driver get?

-BARSIC- [3]

The car's average <em>speed</em> is 97 km/hr.

Then for calculation purposes, we can assume that it covers 97 km in the
first hour, 97 km in the second hour, 97 km in the third hour, and 97 km in
the fourth hour.

All together, the car covers (97 x 4) = <em>388 km</em> of distance.

We don't know the car's velocity, because we have no information about the
<em>direction</em> it moved at any time during the four hours. So we have no way to
calculate how far it was from the starting point at the end of the fourth hour.
For all we can tell, if the direction (and therefore the velocity) varied just right,
the car could have ended up exactly where it started.

5 0

3 years ago

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A player kicks a football from ground level with a velocity of 26.2m/s at an angle of 34.2° above the horizontal. How far back f

Amanda [17]

For the ball to go straight into the goal, the kicker needs to be no more than 6.54 meters away from the goal.

For the ball to arc into the goal, the kicker needs to be between 58.5 and 65.1 meters away from the goal.

<h3>Explanation</h3>

How long does it take for the ball to reach the goal?

Let the distance between the kicker and the goal be $x$ meters.

Horizontal velocity of the ball will always be $26.2\times\cos{34.2\textdegree}$ until it lands if there's no air resistance.

The ball will arrive at the goal in $\displaystyle \frac{x}{26.2\times\cos{34.2\textdegree}}$ seconds after it leaves the kicker.

What will be the height of the ball when it reaches the goal?

Consider the equation

$\displaystyle h(t) = -\frac{1}{2}\cdot g\cdot t^{2} + v_{0,\;\text{vertical}} \cdot t + h_0$ .

For this soccer ball:

$g = 9.81\;\text{m}\cdot\text{s}^{-2}$ ,
$v_{0,\;\text{vertical}} = 26.2\times \sin{34.2\textdegree{}}\;\text{m}\cdot\text{s}^{-2}$ ,
$h_0 = 0$ since the player kicks the ball "from ground level."

$\displaystyle t=\frac{x}{26.2\times\cos{34.2\textdegree}}$

when the ball reaches the goal.

$\displaystyle h= - 9.81 \times \frac{x^2}{(26.2\times\cos{34.2\textdegree})^2} + (26.2 \times \sin{34.2\textdegree})\times\frac{x}{26.2\times\cos{34.2\textdegree}} \\\phantom{h} = -\frac{9.81}{(26.2\times\cos{34.2\textdegree})^2}\cdot x^{2} + \frac{\sin{34.2\textdegree}}{\cos{34.2\textdegree}}\cdot x$ .

Solve this quadratic equation for $x$ , $x > 0$ .

$x = 65.1$ meters when $h = 0$ meters.
$x = 6.54$ or $58.5$ meters when $h = 4$ meters.

In other words,

For the ball to go straight into the goal, the kicker needs to be no more than 6.54 meters away from the goal.
For the ball to arc into the goal, the kicker needs to be between 58.5 and 65.1 meters away from the goal.

3 0

3 years ago

According to x-ray observations, the space between galaxies in a galaxy cluster is?

crimeas [40]

According to x-ray observations, the space between galaxies in a galaxy cluster is very hot. It is because the matter between galaxies (often called the intergalactic medium) is mostly hot, ionized hydrogen with bits of heavier elements such as carbon, oxygen and silicon thrown in.

Massive structures are collapsing than at earlier times. Large collapsing structures lead to higher velocity intergalactic shocks and, as a result, significant intergalactic shock heating, with some gas heated well above the $10^{4}$ K temperatures.

Heating also occurs as galaxies expel out most of the gas that fell into them. The final product is a warm/hot phase, with temperatures of > $10^{5}$ K.

Now, Let's know how do you use X-rays to make space observations?

X-radiation is absorbed by the Earth's atmosphere, so instruments to detect X-rays must be taken to high altitude by balloons, sounding rockets, and satellites.

To learn more about Galaxy Cluster, here

brainly.com/question/16557484

#SPJ4

6 0

2 years ago

Using the periodic table, choose the more reactive metal. Al or Mg

ziro4ka [17]

Aluminum, and magnesium are metals. For metals, reactivity decreases as you go from left to right across the periodic table. Atomic number of Al is 13 and of Mg is 12. Hence the least reactive of these two is therefore aluminum.

Magnesium is "HIGHLY FLAMMABLE" carefully take a small piece and hit it with a torch. If its Magnesium it will "Caution, very, quickly burn.
Aluminum will not react to simple flame, it will only melt with enough direct heat.

Magnesium
==========
Atomic Number: 12
Atomic Symbol: Mg
Atomic Weight: 24.305
Electron Configuration: 2-8-2

Aluminum
========
Atomic Number: 13
Atomic Symbol: Al
Atomic Weight: 26.9815
Electron Configuration: 2-8-3

Hope this helps some. Any questions please feel free to ask. Thank you

6 0

3 years ago

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