The Big Bang probably occurred.
~30,000 B.C. North America Asian hunter-gatherers had crossed over the frozen Bering Strait to become first humans in North America.
~10,000 B.C. South America Those who crossed over on Bering Strait into North America had traveled as far south as Argentina by this point.
~6,000 B.C. Europe End of land bridge between Britain and continental Europe. Britain becomes an island.
~4,500 B.C. Brittany (France) The megalithic structures of Carnac were built.
~3,500 B.C. Wales Pentre Ifan is built.
~3,200 B.C. Ireland The Newgrange tomb is built.
In order to determine the mass of a substance given the volume, we require the density. The density of iron is 7.87 grams/cm³
Now,
Density = mass / volume
Mass = density * volume
Mass = 7.87 * 4.6
36.2 grams of iron are present in the cube
A 72 kg athlete climbs a rope to a height of 12m. Calculate the increase in gravitational potential energy it has experienced.
Answer:
8467.2J
Explanation:
Given parameters:
Mass of the athlete = 72kg
Height of the climb = 12m
Unknown:
Increase in gravitational potential energy it has experienced = ?
Solution:
Gravitational potential energy is the energy due to the position of a body. It is mathematically expressed as;
Gravitational potential energy = m x g x h
m is the mass
g is the acceleration due to gravity = 9.8m/s²
h is the height
Insert the parameters and solve;
Gravitational potential energy = 72 x 9.8 x 12
GPE = 8467.2J
These are dissolved in water to form colourless solutions, and then mixed together. This mixing leads to a double displacement reaction, essentially resulting in the metals 'swapping' their places in the two compounds, producing lead (II) iodide, and potassium nitrate.
