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Tju [1.3M]
2 years ago
7

The rock falls from the distance of 15 m before it hits the water. Calculate its kinetic energy just before hitting the water. S

how your working
Physics
2 answers:
yarga [219]2 years ago
7 0

Answer:

8.57m

Explanation:

v²=u²+2as

then1/2mv²

UkoKoshka [18]2 years ago
6 0

Answer:

k.e =  \frac{1}{2} m {v}^{2}  \\    {v}^{2}  =  {u}^{2}   +  2gs \\  {v}^{2}  = 0  + (2 \times 9.8 \times 15) \\ v = 17.1 \: m {s}^{ - 1}  \\ k.e =  \frac{1}{2}  \times m \times  {17.1}^{2}  \\  = 147m \: joules \\ m \: is \: mass

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zimovet [89]
V = 340 m/s
f = 256 Hz
lambda (wavelength)

v = f*lambda
340 = 256 * lambda
340/256 = lambda
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The international Space Station (ISS) orbits the Earth once every 90 mins at an altitude of 409 km. How high would it have to be
Oksi-84 [34.3K]

It would have to be 36,719 Km high in order to be to be in geosynchronous orbit.

To find the answer, we need to know about the third law of Kepler.

<h3>What's the Kepler's third law?</h3>
  • It states that the square of the time period of orbiting planet or satellite is directly proportional to the cube of the radius of the orbit.
  • Mathematically, T²∝a³
<h3>What's the radius of geosynchronous orbit, if the time period and altitude of ISS are 90 minutes and 409 km respectively?</h3>
  • The time period of geosynchronous orbit is 24 hours or 1440 minutes.
  • As the Earth's radius is 6371 Km, so radius of the ISS orbit= 6371km + 409 km = 6780km.
  • If T1 and T2 are time period of geosynchronous orbit and ISS orbit respectively, a1 and a2 are radius of geosynchronous orbit and ISS orbit, as per third law of Kepler, (T1/T2)² = (a1/a2)³
  • a1= (T1/T2)⅔×a2

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Thus, we can conclude that the altitude of geosynchronous orbit is 36,719km.

Learn more about the Kepler's third law here:

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An airplane pilot flies due west at a speed of 216 km/hr with respect to the air. After flying for a half an hour, the pilot fin
Yuki888 [10]

Answer:

speed wind  Vw = 54.04 km / h   θ = 87.9º

Explanation:

We have a speed vector composition exercise

In the half hour the airplane has traveled X = 108 km to the west, but is located at coordinated 119 km west and 27 km south

Let's add the vectors in each coordinate axis

   

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      Xw = -Xavion + 119

      Xw = 119 -108

      Xwi = 1 km

Calculate the speed for time of  t = 0.5 h

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Y Axis (North-South)

    Y plane - Yi = -27

    Y plane = 0

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Let's use the Pythagorean theorem and trigonometry to compose the answer

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The speed direction is 87. 9th measure In the third quadrant of the X axis in the direction 90-87.9 = 2.1º  west from the south

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Zielflug [23.3K]
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2 years ago
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