Answer: The area of the edge of a knife's blade is extremely small.
Syringes are used to take blood for blood tests.
When air is sucked out of a drinking straw, the air pressure inside if decreases and the atmospheric pressure outside forces the liquid to go inside the straw.
Explanation:
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: Atomic number, Atomic Mass, Ionic radius
Explanation:
Answer:
changing the polarity or direction of the battery changes the sign of the voltage and the current
Explanation:
The sign of current and voltage are due to established conventions.
The way that a DC circuit with negative current values is by changing the polarity of the power source or by inverting the battery, this creates that the electrons move in the opposite direction
Changing the battery also changes the direction of the power difference, since the potential from positive to negative, in most cases negative is assigned a potential of zero volts
In summary, changing the polarity or direction of the battery changes the sign of the voltage and the current
