Thermal-energy flow between objects is conserved and always flows from the warmer object to the cooler object.
Here 'conserved' means that the amount of thermal energy lost of by one body is exactly equal to the amount of thermal energy gained by another body, which is the statement of the first law.
According to second law, we do not see objects warming up on their own. For example, if we have a cup of coffee left to itself, we would always see that it cools down. Here, thermal energy is being transferred from warmer object (coffee) to cooler objects (the air in the room).
When you talk about rate, you will expect that it will be in terms of a time unit. It measures how fast it is going. So, you would expect that the denominator is in time units. For the movement, you can measure this with either distance or velocity.
So, for the first variety, you would need distance and time to measure the rate of how far you go at a certain time. It is also called as velocity. For the second variety, you would need velocity and time to measure the rate of how fast you are going at a certain interval. It is also called as acceleration.
Answer:
Technician A is right, because the lubrication system in a two-stroke engine requires mixing with the fuel, therefore oil is constantly burned, while a 4-stroke engine has a separate lubrication system.
Technician B is wrong, usually the 2-stroke engines are small and the cooling system is that the cylinder container is constructed with a geometry that allows to increase the area of heat transfer called fins, this allows to release heat quickly .
Answer:
80%
Explanation:
Thermal efficiency is a measure of the extent to which a heat engine is able to convert to other form. It is measure in percentage.
Thermal efficiency = 
× 100%
Where 
is the input energy and 
is the output energy.
Given that: = 2400 J and = 3000 J, therefore:
Thermal efficiency = 
× 100%
= 80%
The thermal efficiency of the engine is 80%.
