The burner in a hot air balloon adds 6400 J of heat to the balloon while the ballon expands. As the balloon expands, it does 3100 J of work on the surrounding air. What is the internal change in thermal energy of the balloon?

the change in the internal energy of the balloon is 3,300 J

Explanation:

Given;

heat gained by the balloon system, Q = 6,400 J

work done on the surrounding air by the balloon, W = 3,100 J

The change in the internal energy of the system is calculated from the first law of thermodynamics;

ΔU = Q - W

where;

ΔU is the change in the internal energy of the balloon;

ΔU = 6,400 J - 3,100 J

ΔU = 3,300 J

Therefore, the change in the internal energy of the balloon is 3,300 J

force is mass*acceleration.

we have a very small mass: 11.4*0.001 kg

if we want 0.035n of force, we need an acceleration:

0.035 = 11.4*0.001*a

a = 0.035/(11.4*0.001) m/s^2