A large research balloon containing of helium gas at 1.00 and a temperature of 15.0 rises rapidly from ground level to an altitude at which the atmospheric pressure is only 0.900 (the figure (Figure 1) ). Assume the helium behaves like an ideal gas and the balloon's ascent is too rapid to permit much heat exchange with the surrounding air. What is the change in internal energy of the helium as the balloon rises to the higher altitude?