Answer:
A
I think I've read this passage before
Graphite is great lubricant because each carbon atom forms weak covalent bonds with three other carbon atoms.
Diamond and graphite both are entirely made up of carbon but both the elements are completely different because of the bonding of carbon atoms. In graphite the carbon atoms form weak covalent with the other three carbon atom due to which there is less or no force between the atoms, and makes the graphite very soft and slippery, and graphite act as lubricant.
The answer is false..................
Answer: The gauge pressure of the air in the tires is 179.5 kPa.
Solution :
Combined gas law is the combination of Boyle's law, Charles's law and Gay-Lussac's law.
The combined gas equation is,
where,
= initial pressure of gas = Atmospheric pressure + gauge pressure = 101 kPa + 165 kPa = 266 kPa
= final pressure of gas = ?
= initial volume of gas =
= final volume of gas =
= initial temperature of gas =
= final temperature of gas =
Now put all the given values in the above equation, we get the final pressure of gas.
Gauge pressure = Absolute pressure - atmospheric pressure = (280.5 - 101) kPa= 179.5 kPa
Therefore, the gauge pressure of the air in the tires is 179.5 kPa.
Speed = distance/time
Speed of car = 125 km/2 hours
Car speed = 62.5 km/hr.