Answer:

is time required to heat to boiling point form initial temperature.
Explanation:
Given:
initial temperature of water, 
time taken to vapourize half a liter of water, 
desity of water, 
So, the givne mass of water, 
enthalpy of vaporization of water, 
specific heat of water, 
Amount of heat required to raise the temperature of given water mass to 100°C:



Now the amount of heat required to vaporize 0.5 kg of water:

where:
mass of water vaporized due to boiling


Now the power rating of the boiler:



Now the time required to heat to boiling point form initial temperature:


Answer:
The answer is B
Explanation:
The line spectrum shows distinct light different energies and wavelengths
Ans: a = 2.50 m/s^2
Explanation:
First convert the mass in its standard unit i.e. kilogram(kg):
2250 lbs = 1020.583kg
Next use Newton's Second law:
F = ma
Where F = 2552N
m = 1020.583kg
=> a = (2552/1020.583)
a = 2.50 m/s^2
<span>Weight is directly proportional to mass.</span>
<span> energy produced by flow of electric charge describes a electrical energy
because movement of electric charge do effect the work on system
so correct option is B
hope it helps</span>