Answer:
The star-sphere discovered by the Greeks and other ancient civilizations which shows the physical location in space of the nearby stars.
Explanation:
The celestial sphere is an ideal sphere, without defined radius, concentric with the terrestrial globe, in which the stars apparently move. Some ancient civilizations such as the Greeks assumed that the stars were attached to a celestial sphere, which revolves around the earth, while our planet is always immobile.
Answer:
Explanation:
Kinetic energy at the height = 1/2 m v²
= 1/2 x 750 x 20²
= 150000 J
Its potential energy = mgh
= 750 x 9.8 x 5
=36750 J
Total energy = 186750 J
Its total kinetic energy will be equal to 186750 J , according to conservation of mechanical energy
If v be its velocity at the bottom
1/2 m v² = 186750
v = √498
= 22.31 m /s
What well u can use to make a shelter but that's all I can think of ??
Answer: 10.96secs
Explanation:
According to newton's second law
Force = mass × acceleration
F = ma
F = m(v-u)/t
Cross multiplying we have
Ft = m(v-u)
t = m(v-u)/F
Given F = 2600N m = 19,000kg v = 1.5m/s u = 0m/s
Substituting this values in the formula for the time we have
t = 19000(1.5-0)/2600
t = 28,500/2600
t= 10.96secs
