Question

6. Assume that the pressure inside of the 1 liter balloon is 200,000 Pa, what is the explosive energy in the inside the balloon? Express your answer in joules and pounds of TNT (2.1x106 J 1 lb of TNT).

Answer 1

As it is given the volume of balloon ,V_i=1 litre =10^-3 m³

and the pressure inside the balloon ,P_i=200,000 Pa

so explosion energy present inside the energy is the energy which would be released if the balloon would burst out means its final volume becomes zero and final pressure becomes equal to atmospheric pressure.

So Explosive energy inside the balloon=(P_iV_i)-(P_fV_f)

As final volume becomes 0 so (P_fV_f)=0

Explosive energy inside the balloon=(P_iV_i)=200,000*10^-3=200 Joules

As it is given 2.1 *10⁶ J of energy =1 lb TNT

So 200 J of energy =200/(2.1*10⁶)=9.52*10^-5 lb TNT