If you heat that air by 100 degrees F, it weighs about 7 grams less. Therefore, each cubic foot of air contained in a hot air balloon can lift about 7 grams. That's not much, and this is why hot air balloons are so huge -- to lift 1,000 pounds, you need about 65,000 cubic feet of hot air.
Complete question:
A diver is 10 m below the surface of water. Calculate the pressure the fluid exerted on the diver. The acceleration of gravity is 9.8 m/s2 and the density of the water is 1000 kg/m3. Answer in units of Pa. Show your work.
Answer:
Tthe pressure the fluid exerted on the diver is 1.99 x 10⁵ Pa
Explanation:
Given;
density of water, ρ = 1000 kg/m³
diver's position below the surface of the water, h = 10 m
acceleration due to gravity, g = 9.8 m/s²
Let the atmospheric pressure, P₀ = 101325 Pa
The pressure 10 m below the surface of the water is calculated as;
P = P₀ + ρgh
P = 101325 Pa + (1000 x 9.8 x 10)Pa
P = 199325 Pa
P = 1.99 x 10⁵ Pa.
Therefore, the pressure the fluid exerted on the diver is 1.99 x 10⁵ Pa
Electrostatic forces between charges depend on the product of
the sizes of the charges, and the distance between them.
We should also mention the item about whether the charges are
both the same sign or opposite signs. That determines whether
the forces will pull them together or push them apart, which is a
pretty significant item.
If a force always acts perpendicular to an object's direction of motion, that force cannot change the object's kinetic energy. It is a true statement .
Kinetic energy is the energy that an object possesses due to its motion. It is basically the energy of mass in motion. Kinetic energy can never be negative and it is a scalar quantity i.e. it provides only the magnitude and not the direction.
According to law of conservation of mechanical energy change in potential energy is equal and opposite to the change in the kinetic energy.
According to the principle of conservation of mechanical energy, The total mechanical energy of a system is conserved i.e., the energy can neither be created nor be destroyed; it can only be internally converted from one form to another if the forces doing work on the system are conservative in nature.
since, potential energy is stored in the form of work done
Work done = Fs cos (theta)
If force always acts perpendicular to an object's direction of motion
theta = 90 °
cos (90 ) = 0
Work done = 0
since , there is no work done , hence kinetic energy will not change
To learn more about kinetic energy here
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