Please remember to post in the right category next time :)
.40 as a fraction is 4/10 or 2/5
the 4 is in the tenths place, so put it over a 10 to make it a fraction.
then, simplify the fraction by dividing the numerator and denominator by 2, and you get 2/5
<h2>Answer: Venus</h2>
Galileo was the first to use the telescope to observe the heavens, mainly observing the Moon, the Sun with its sunspots, Jupiter with its moons and Venus (in the early 1600s).
In the case of Venus, he observed that it presented phases (such as those of the moon) together with a variation in size; observations that are only compatible with the fact that Venus rotates around the Sun and not around Earth.
This is because Venus presented its smaller size when it is in full phase and the largest size when it is in the new one, when it is between the Sun and the Earth.
These images along with other discoveries were presented to the Catholic Church (which supported the <u>geocentric theory</u> for that time) as a proof that completely refutes Ptolemy's geocentric system and affirms <u>Copernicus' heliocentric theory.</u>
Okay first you have to recognize that the maximum Gravitational potential energy will equal the maximum kinetic energy. The maximum GPE will equal when the stone is at its highest point and the max KE will be right before the stone hits the ground. So
GPE max = KE max
mgh = 1/2mv^2
Mass cancels as it is on both sides
gh = 1/2v^2
Multiply by 2
2gh = v^2
Square root
v = √2gh
Now plug in
v = √2(9.8)(4)
v = 8.85 m/s
Now use the mass to calculate the momentum just before it hits the ground as this is the speed right before it hits the ground
p = mv
p = (3)(8.85)
p = 26.55 kgm/s
