Sledgehammer and Baseball Bat Revisions

[Podonklos]

Currently, the sledgehammer is rated as Wall Class at "full potential" while a baseball bat is rated as being Street Class, with this calculatio being linked to support that.

While the baseball bat's current Class is fine, the calculation used to support it is flawed for a couple reasons.

1. Its figure for the baseball bat's swing velocity is wrong. What the article linked in that calculation is measuring is the velocity of the baseball after being hit, which is greater than the velocity of the bat hitting it.
2. The calculation models the baseball bat as a mass moving at a uniform, linear velocity of 55+ m/s, which isn't the case. Some parts of the baseball bat are moving faster than others, due to being further from the pivot point. The proper equation here would be the equation for rotational kinetic energy, not the equation for linear kinetic energy.

To replace the baseball bat's justification, I found these two sources. The first contains a screenshot from the Mythbusters, which lists the energy behind a baseball bat as being around 580 Joules. The second article lists a figure from The Physics of Baseball, which claims that baseball bats are swung with, rounding, 450 Joules of energy. In either case, the energy behind a baseball bat swing seems to be around 500 Joules, not over 1000.

The issue with the sledgehammer article is just a matter of scale. A human swing, regardless of the object, just can't reach the 15,000 Joules necessary to be in Wall Class.

Recall, the formula for rotational kinetic energy is K = Iw2/2. If the moment of inertia for a sledgehammer is an incredible 3 kg m2 and the target energy is 15,000 Joules, then this hypothetical "full potential" human would be swinging the sledgehammer with an angular velocity of 100 rad/s. To put this in scale, this is far faster than even baseball bats are swung.

To summarize, the baseball bat article needs new justifications, and the sledgehammer article needs its Wall Class listing removed.

 

[Amelia_Lonelyheart]

These changes seem fine.

 

[Podonklos]

I found this article, which says that "a strong man can swing a sledgehammer with a mass of 5 Kg to a kinetic energy of about 500 joules", which supports the conclusion in my OP. They don't specify how they measured the figure though, unfortunately.

 

[Antoniofer]

Its about right, I agree with the changes.

 

[This_is_My_Username_was_taken]

slegehammer is 8-b

 

[Matthew_Cabrão]

sledgehammer is 8-b

 

[This_is_My_Username_was_taken]

sledgehammer is 8-b

Top 10 anime facts

 

[Soupywolf5]

Necro, because this seems to have just died without a conclusion being reached

 

[GyroNutz]

OP seems fine

 

[Everyone_is_die]

would a power drill be street level

 

[KLOL506]

Not really why a sledgehammer is 9-B tho. It's 9-B for smashing skulls. And breaking holes into walls. Feats come before KE.

Also this is a necro. Someone should close this thread.

 

[Mr. Bambu]

Curses upon all of your houses.

Goodbye thread.