<span>You could easily define it this way. This would be valid. But for most of history it was unclear when a baby was conceived, so it would be silly for someone to say their baby was 9 months old when it was actually born at only 8.5 months. Days of conception similarly would not be a good substitute for birthdays because no one would know them. Then in general it was much easier to mark someone's age as when they came into the world as an independent being, and this tradition is far too entrenched (and simple and easy to handle and universal for people in poor countries etc) to think we would at all gain from now finding exactly the date of conception and counting age from that point.</span>
Answer: A medium is any substance or region through which a wave is transmitted. The speed of a wave is dependant on four factors: wavelength, frequency, medium, and temperature. Wave speed is calculated by multiplying the wavelength times the frequency (speed = l * f).
Kepler noticed an imaginary line drawn from a planet to the Sun and this line swept out an equal area of space in equal times, If we then draw a triangle out from the Sun to a planet’s position at one point in time, it is notice that the area doesn't change even after the planet has left the original position say like after 2 to 3days or 2hours. So to have same area of triangle means that the the planet move faster when that are closer to the sun and slowly when they are far from the sun.
This led to Kepler's law of orbital motion.
First Law: Planetary orbits are elliptical with the sun at a focus.
Second Law: The radius vector from the sun to a planet sweeps equal areas in equal times.
Third Law: The ratio of the square of the period of revolution and the cube of the ellipse semi-major axis is the same for all planets.
It is this Kepler's law that makes Newton to come up with his own laws on how planet moves the way they do.
Answer:
Being a plane mirror the Image is formed 3 metres beyond the mirror . So total distance is 3+3 = 6metres
Water waves are not radiant energy. Therefore C is the right answer. Water waves have momentum and energy like electromagnetic waves but don't classify as radiant energy.
