A toy helium balloon is initially at a temperature of T = 20o C. Its initial volume is 0.0042 m3 (It is a 10 cm radius sphere). Assume that the pressure in the balloon always equals atmospheric pressure, 101.3 kPa.
1) The balloon is lying in the sun, which causes the volume to expand by 6%. What is the new temperature,
T = ?
2) By how many Joules did the internal energy of the gas in the balloon increase?
ΔU = ?
3) How much work was done by the gas during the expansion? (It's a positive number.)
Wby =
4) How much heat was added to the gas by the Sun?
Q =