Answer:
Let No be initial no of atoms
N = N0 / 2 after 1 half-life
N = N0 / 4 after 2 half-lives
So after 2 half-lives 20 of the 80 atoms remain
1.8 mol of Na. hope this helps
W = mg, Assuming g ≈ 9.8 m/s² on the earth surface.
735 N = m* 9.8
735/9.8 = m
75 = m
Mass , m = 75 kg. B.
The angle at which the sunlight received at a location on Earth spread out over the largest area is 10°. Last option is correct.
<h3>What is sunlight?</h3>
The light coming from the Sun reaching the Earth's surface is called as Sunlight.
When the sun is overhead, the intensity is high because sun's rays are perpendicular to the earth's surface, so the energy spreads over a small area and the heat is too high in that region.
When, the angle is smaller, the sunlight will spread out over a larger area.
Thus, at 10° the sunlight received at a location on Earth spread out over the largest area. Last option is correct.
Learn more about Sunlight.
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Answer:
8.8 kN
Explanation:
V = 2 m³, W = 40 kN, SG = 1.59
Bouyant force N = 1.59 * 1000 kg/m³ * 9.81 N/kg * 2 m³ = 31.2 kN
So the weight becomes 40 - 31.2 = 8.8 kN
