To solve this problem we will apply the concepts related to the thermal efficiency given in an engine of the Carnot cycle. Here we know that efficiency is given under the equation

Where,
Temperature of Cold Body
Temperature of Hot Body
= Efficiency
According to the statement our values are:


Replacing we have that




Therefore the temperature of the heat source is 300K
Answer: D. An action-reaction force pair
Explanation: When you sit in your chair, your body exerts a downward force on the chair and the chair exerts an upward force on your body. There are two forces resulting from this interaction - a force on the chair and a force on your body. Another example would be a person pushing against a wall (action force), and the wall exerts an equal and opposite force against the person.
Answer:
I think it is difficult to determine what has caused climate change in the distant past because it must have been a long time ago so geologists can't carry out different experiments and figure out what gases the planet had conjured, so geologists can only make predictions based off the evidence they currently have from what the planet looked like before. The planet must have changed over the years, therefore the climate has also changed in the future, so they cannot work with how the planet looked in the past.
Answer:
Thats a personal question
Explanation:
It asks about you
(illusion is something you think is there but is not)