Work needed = 23,520 J
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Further explanation
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Given
height = 12 m
mass = 200 kg
Required
work needed by the crane
Solution
Work is the transfer of energy caused by the force acting on a moving object
Work is the product of force with the displacement of objects.
Can be formulated
W = F x d
W = Work, J, Nm
F = Force, N
d = distance, m
F = m x g
Input the value :
W = mgd
W = 200 kg x 9.8 m/s²x12 m
W = 23520 J
Answer:<span>Humid air is lighter, so it has lower pressure.
The reason is the molecules of water are H2O, whose molar mass is 18 g/mol.
These molecules displaces molecules of N2 and O2, whose molar masses are:
N2: 2*14g/mol = 28 g/mol, and
O2: 2*16g/mol = 32 g/mol.
Then molecules of 28g/mol and 32 g/mol are being replaced with molecules of 18g/mol, leading to a lower weight of the same volume of air, which results in lower pressure.
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Answer:
<em> think 2 also if not im so sorry but i think it is :)</em>
