Question 1 of 7What is the change in internal energy if 90 J of thermal energy is added to asystem, and the system does 30 J of
1 answer:
Given:
The thermal energy added to the system is Q = 90 J
The work done by the system on the surroundings is W = 30 J
To find the change in internal energy.
Explanation:
According to the first law of thermodynamics, the change in internal energy can be calculated by the formula
On substituting the values, the change in internal energy will be
Final Answer: The chage in internal energy is 60 J (option D)
You might be interested in
We know that arc length (x(t)) is given with the following formula:
Where r is the radius of the barrel. We must keep in mind that as barrel rolls its radius decreases because less and less tape is left on it.
If we say that the thickness of the tape is D then with every full circle our radius shrinks by d. We can write this down mathematically:
When we plug this back into the first equation we get:
We must solve this quadratic equation.
The final solution is:
It is rather complicated solution. If we asume that the tape has no thickness we get simply:
Where r is the radius of the barrel. We must keep in mind that as barrel rolls its radius decreases because less and less tape is left on it.
If we say that the thickness of the tape is D then with every full circle our radius shrinks by d. We can write this down mathematically:
When we plug this back into the first equation we get:
We must solve this quadratic equation.
The final solution is:
It is rather complicated solution. If we asume that the tape has no thickness we get simply: