In the Dreamworks movie Monsters vs Aliens, Susan kicks B.O.B. into the air and he does not come down for 41 seconds (0:09 to 0:50 of this video)
I'll be calculating his durability based off of this. But in order to do this I'll be making a few assumptions. In the movie it is stated that he is made of a substance called Benzoate ostylezene bicarbonate, which does not exist. However, it is also stated that he was made by combining genetically altered ranch dressing with a genetically altered tomato. Both tomatoes and ranch dressing have sodium benzoate in them. With that in mind, I'll use the density of sodium benzoate (1.5 g/cm^3) as well as the volume I calculate for B.O.B. down below to find his mass.
Susan is 49 feet and 11 inches or 1521 cm tall. B.O.B. is vaguely cylindrical.
If you need to know how I got the rest of the values I'll be using, feel free to ask.
Volume of a cylinder is V = pi*r^2*h
3.14*(82.8477653631^2)*246.418994413 = 5.31x10^6 cm^3
(5.31x10^6) x 1.5 = 7965000 g or 7965 kg
E = 0.5*7965*(9.81*20.5)^2 = 1.61x10^8 joules or Small Building level
ZanyBrainy's Adjustment[]
Looking at the variables included, I presume you guessed that half of the flight - 20.5 seconds- was spent flying upwards, and the other half was expended falling down. I do not believe kinetic energy would be applicable, as this is a feat where an object is falling to the ground via the effects of gravity, so the gravitational potential energy formula would better suit this situation.
20.5 x 9.81 = 201.10500 meters off of the ground mid-point
9.81 * 7965 * 201.10500 = 1.5713671 x 10^7 joules, or 3.7556575 kilograms of TNT
Wall level+, really high-end wall level, too