Testing the electrical resistance of different materials. it is the answer
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 potential energy increases and the kinetic energy decreases
Answer:
gamma rays, ultraviolet, infrared, radio
Explanation:
Because on the Electromagnetic spectrum wavelength increases from the gamma end to radio end and frequency decrease in that order
Answer:
40N in either direction is the answer