Air in a balloon does 50 J of work while absorbing 70 J of heat.What is its change in internal energy?
To find the change in internal energy, we need to apply the First Law of Thermodynamics, which states that the change in internal energy of an object is equal to the heat added to the object minus the work done by the object:
ΔU = Q - W
where:
ΔU = change in internal energy
Q = heat added to the object
W = work done by the object
In this case, the balloon is doing work, which means it is losing energy. Therefore, the work done by the balloon is negative (-50 J), and heat is being absorbed by the balloon (Q = 70 J).
Substituting these values into the equation, we have:
ΔU = 70 J - (-50 J)
ΔU = 70 J + 50 J
ΔU = 120 J
Therefore, the change in internal energy of the balloon is 120 Joules.