Answer:
Free convection:
When heat transfer occurs due to density difference between fluid then this type of heat transfer is know as free convection.The velocity of fluid is zero or we can say that fluid is not moving.
Force convection:
When heat transfer occurs due to some external force then this type of heat transfer is know as force convection.The velocity of fluid is not zero or we can say that fluid is moving in force convection.
Heat transfer coefficient of force convection is high as compare to the natural convection.That is why heat force convection reach a steady-state faster than an object subjected to free-convection.
We know that convective heat transfer given as
q = h A ΔT
h=Heat transfer coefficient
A= Surface area
ΔT = Temperature difference
Harmonic excitation refers to a sinusoidal external force of a certain frequency applied to a system. ... Resonance occurs when the external excitation has the same frequency as the natural frequency of the system. It leads to large displacements and can cause a system to exceed its elastic range and fail structurally.
The French and Dutch colonized arenas so small compared to the Spanish colonized areas For farming
Answer:
concentration of Mg ion = 0.0122 g/L
Explanation:
Given data;
initial concentration of Magnesium in water is 40 mg/l
concentration of 
we have dissociation reaction Magnesium dioxide

from above reaction we can conclude
concentration of 
Mass of magnesium ion is calculated as = Mg mole * molar mass of magnesium
concentration of Mg ion = 0.0005*24.305 g/mol = 0.0122 g/L
Answer:
The stand-by equipment is technically required in case where the we need some urgent equipment for the purpose of maintenance in emergency and if the other equipment system get fails. the term stand by means backup equipment and component.
In the reliability engineering, we always need to provide an extra equipment or component in case of emergency. It is basically used so that it does not affect any type of productivity in the organization. It is also increase the redundancy of the equipment.