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1 year ago

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Allison stands 180 meters away from a steep canyon wall. She shouts and hears the echo of her voice one second later. What is th

e speed of the wave?

1 answer:

ratelena [41]1 year ago

3 0

Answer:

V = S / t speed of wave

V = 2 * 180 m / 1 sec = 360 m/s speed of sound wave

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Suppose that, while lying on a beach near the equator of a far-off planet watching the sun set over a calm ocean, you start a st

zubka84 [21]

Answer:

R=3818Km

Explanation:

Take a look at the picture. Point A is when you start the stopwatch. Then you stand, the planet rotates an angle α and you are standing at point B.

Since you travel 2π radians in 24H, the angle can be calculated as:

$\alpha =\frac{2*\pi *t}{24H}$ t being expressed in hours.

$\alpha =\frac{2*\pi *11.9s*1H/3600s}{24H}=0.000865rad$

From the triangle formed by A,B and the center of the planet, we know that:

$cos(\alpha )=\frac{r}{r+H}$ Solving for r, we get:

$r=\frac{H*cos(\alpha) }{1-cos(\alpha) } =3818Km$

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2 years ago

a stone is dropped from the top of 50 m high tower simultaneously another stone is thrown upward with a speed of 20 m/s . calcul

Darina [25.2K]

'H' = height at any time
'T' = time after both actions
'G' = acceleration of gravity
'S' = speed at the beginning of time
Let's call 'up' the positive direction.
Let's assume that the tossed stone is tossed from the ground, not from the tower.

For the stone dropped from the 50m tower:

H = +50 - (1/2) G T²

For the stone tossed upward from the ground:

H = +20T - (1/2) G T²

When the stones' paths cross, their <em>H</em>eights are equal.

50 - (1/2) G T² = 20T - (1/2) G T²

Wow ! Look at that ! Add (1/2) G T² to each side of that equation,
and all we have left is:

50 = 20T Isn't that incredible ? ! ?

Divide each side by 20 :

<u>2.5 = T</u>

The stones meet in the air 2.5 seconds after the drop/toss.

I want to see something:
What is their height, and what is the tossed stone doing, when they meet ?

Their height is +50 - (1/2) G T² = 19.375 meters

The speed of the tossed stone is +20 - (1/2) G T = +7.75 m/s ... still moving up.
I wanted to see whether the tossed stone had reached the peak of the toss,
and was falling when the dropped stone overtook it. The answer is no ... the
dropped stone was still moving up at 7.75 m/s when it met the dropped one.

7 0

2 years ago

The majority of the nitrogen on earth can be found in which reservoirs?

xz_007 [3.2K]

Answer:

atmosphere

Explanation:

majority of nitrogen found in atmosphere,it's about 78% and present in form of gas

8 0

2 years ago

Five factors predisposing a person to stroke

insens350 [35]

Answer:

the answers maybe→↓

Explanation:

high blood pressure.

cigarette smoking.

diabetes.

high blood cholesterol levels.

heavy drinking.

5 0

2 years ago

Read 2 more answers

Reactance Frequency Dependence: Sketch a graph of the frequency dependence of a resistor, capacitor, and inductor. RLC Circuit R

jolli1 [7]

Answer:

$f=\frac{1}{2\pi \sqrt{LC}}$

Explanation:

We know that impedance of a RLC circuit is given by $Z=R+J(X_L-X_C)$

So $Z=\sqrt{R^2+(X_L-X_C)^2}$ here R is resistance $X_L$ is inductive reactance and $X_C$ is capacitive reactance

To minimize the impedance $X_L-X_C$ should be zero we know that $X_L=\omega L\ and \ X_C=\frac{1}{\omega C}$

So $\omega L-\frac{1}{\omega C}=0$

$\omega ^2=\frac{1}{LC}$

$\omega =\sqrt{\frac{1}{LC}}$

We know that $\omega =2\pi f$

So $\omega =2\pi f=\frac{1}{\sqrt{LC}}$

$f=\frac{1}{2\pi \sqrt{LC}}$

Where f is resonance frequency

8 0

2 years ago