Answer:
160m/s
Explanation:
The speed of a wave is related to its frequency and wavelength, according to this equation:
v=f ×λ
Answer:
<h3>After 3seconds</h3>
Explanation:
A supersonic aircraft flies at 3 km altitude at a speed of 1000 m/s on a standard day. How long after passing directly above a ground observer is the sound of the aircraft heard by the ground observer
Using the formula for calculating speed expressed as;
Speed = Distance/Time
Given;
Distance = 3km = 3000m
Speed = 1000m/s
Required
How long after passing directly above a ground observer is the sound of the aircraft heard by the ground observer (Time)
From the formula;
Time = Distance/speed
Time = 3000/1000
Time = 3seconds
Hence the sound of the aircraft is heard after 3 seconds
At the ridge, new crust forms by igneous intrusion and extrusion. Since hot rocks are in a more expanded state and then contract as they cool (as they spread away from the ridge), the midocean ridges stand up high above the surrounding seafloor. The seafloor depth increases with distance away from the midocean ridges.
Explanation:
Kepler's third law gives the relationship between the orbital radius and the orbital period of the planet. Its mathematical form is given by :

Here,
G is gravitational constant
M is mass of sun
It means that the mass of Sun is constant for all planets orbiting the sun, assuming circular orbits.
Answer:
Explanation:
In 1789, Antoine Lavoisier published a list of 33 chemical elements. Although Lavoisier grouped the elements into gases, metals, non-metals, and earths, chemists spent the following century searching for a more precise classification scheme. In 1829, Johann Wolfgang Döbereiner observed that many of the elements could be grouped into triads (groups of three) based on their chemical properties. Lithium, sodium, and potassium, for example, were grouped together as being soft, reactive metals. Döbereiner also observed that, when arranged by atomic weight, the second member of each triad was roughly the average of the first and the third.[19] This became known as the Law of Triads.[20] German chemist Leopold Gmelin worked with this system, and by 1843 he had identified ten triads, three groups of four, and one group of five. Jean Baptiste Dumas published work in 1857 describing relationships between various groups of metals. Although various chemists were able to identify relationships between small groups of elements, they had yet to build one scheme that encompassed them all.[19]