This upcoming year, I’m back into the physics saddle (part time, at least) and the summer blockbuster schedule is supplying me plenty of fodder for my Physics of Superheros course.
Witness this scene from X-Men: First Class. (As I eagerly await the DVD release, you’ll have to settle for this single image)
Sebastian Shaw is a mutant. His power is that he can absorb kinetic energy and “rechannel it into superhuman strength, speed and durability“. In this scene, he’s about to absorb the energy of a hand grenade.
Just for argument’s sake, let’s say that’s a popular WWII grenade, the Mk2. The TNT equivalent for the 57 g of TNT in a Mk2 is 240 kJ. In order for normal Kevin Bacon to store that much energy, he’d have to climb to a height of 340 m*. Dude, that’s a lot of energy.
Shaw is a walking, talking example of the Conservation of Energy Theorem. He is so going into my class.
Physics peeps — suppose Shaw chose to convert the energy to “superhuman strength”, how strong would he be? More to the point, what does “strength” mean in this sense? Should we go with traditional materials measures of strength like tensile or ductile? Or human measures like “can bench press x pounds”?
* Energy is conserved and potential energy is given by PE = mgh
m=mass
g=gravity
h=height
Solving for h gives h = PE/(mg)
h = 240 kJ / [(70 kg)(9.8 m/s²)]
h= 340 m
This falls under Georgia Performance Standard SP3a, “Students will evaluate the forms and transformations of energy. a. Analyze, evaluate, and apply the principle of conservation of energy and measure the components of work-energy theorem by
• describing total energy in a closed system.
• identifying different types of potential energy.
• calculating kinetic energy given mass and velocity.
• relating transformations between potential and kinetic energy.”
Megan Hayes-Golding 
The energy the human body uses to power muscle is stored in glucose, glycogen and fat. You could convert the energy output units to calories, and use the standard coversion of calories to grams of glucose/glycogen/fat to determine how much extra mass Shaw would have to acquire to store the energy in a form useful for feats of strength.
You could have fun deciding what proportion of the energy is stored as what chemical. For instance, storing it all as glucose would result in quite spectacular hyperglycemia and possibly ketoacidosis. Over time, it probably do a number on his pancreas and may lead to insulin resistance. There are several different diseases called “glycogen storage disease,” but they mostly seem keyed to various deficiencies; I can’t find anything offhand that talks about the effects of too much glycogen. Of course, we all know what too much fat leads to, and since the body converts excess glucose to fat (I don’t know what it would do if you shot up glycogen), you could probably just think about it in terms of how quickly he could go from Kevin Bacon to Porky Pig.
Oh yeah: that’s just the energy. If his muscles aren’t able to efficiently transmit the energy, he porks up. If they are able to to translate the energy into feats of strength, though, his musculoskeletal system would be pretty special or else his muscles would either rip from his bones or break them.
BTW, Shaw was my favorite member of the Hellfire Club.