We have discovered 786 planets. Most of which were only recently discovered.
The widely accepted hypothesis before that turned out wrong was the Earth-Centered theory or the Geocentric Theory. This was proposed by the philosopher Ptolemy. He came about to this hypothesis from hi observation that from the Earth's perspective, the celestial bodies like the Sun, stars and the moon, look like they rotate around the Earth each day and night. However, this was disproved by Galileo Galelei by his Heliocentric Theory. He observed through the telescope that the Venus also changes phases like the moon. However, he deduced that this is not possible from the positions of the Venus, Earth, Moon and Sun.
Answer:
t = 1.75
t = 0.04
Explanation:
a)
For part 1 we want to use a kenamatic equation with constant acceleration:
X = 1/2*a*t^2
isolate time
t = sqrt(2X / a)
Plugin known variables. Acceleration is the force of gravity which is 9.8 m/s^2
t = sqrt(2*15m / 9.8m/s^2)
t = 1.75 s
b)
The speed of sound travels at a constant speed therefore we don't need acceleration and can use the equation:
v = d / t
isolate time
t = d / v
plug in known variables
t = 15m / 340m/s
t = 0.04 s
True. These are the characteristics of a social drinker.
Newton's 2nd law says: Force = (mass) x (acceleration) .
I wrote Force and acceleration in bold letters because
they're both vectors ... they have size and direction.
The equation is saying that the Force and the acceleration
are both in the same direction.