Answer:
h = 0.362 m
Explanation:
The pressure equation with depth is
P₂ = 
+ρ g h
The gauge pressure is
P2 - = ρ g h
This is the pressure that muscles can create
P₂ - = 3740 Pa
But still the person needs a small pressure for the transfer of gases, so
P₂ - = 3740 - 188 = 3552 Pa
This is the maximum pressure difference, where the person can still breathe,
Let's clear the height
h = 3552 / ρ g
h = 3552 / (1000 9.8)
h = 0.362 m
This is the maximum depth where the person can still breathe normally.
Wind farms, solar collectors, and nuclear power plants generate no pollution.
But wind farms make noise, wind and solar are both hazardous to birds, and there's no known means of disposing of nuclear plant waste that's completely safe.
The last one, handmade gifts require more of the givers time!
Answer:
b) 5 J
Explanation:
Work is the energy transferred by an object when acted by a force along a displacement. Work is the product of force and displacement. The SI unit of work is the joules (J)
To calculate the work done by the force, we have to first get the displacement (D) of the object. Hence:
Displacement (D) = Q(3, 8) - P(1, 3) = (3 - 1, 8 - 3) = (2, 5) = 2i + 5j
The work done is the dot product of the force and the displacement. Force = 5i - j. Hence:
Work done = (5i - j)(2i + 5j) = 10 - 5 = 5 J
