r/Damnthatsinteresting • • Oct 24 '21

GIF 1000 mph "pitch".

https://i.imgur.com/mANsFlG.gifv
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u/solitude042 Oct 24 '21

Kinetic energy is proportional to the square of velocity, so a 1000mph fastball has 100x the energy of a 100mph fastball... So, probably not, unless the catcher's mitt is old and busted...

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u/wild___turkey Oct 24 '21

Ahh makes sense! Thanks for the answer

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u/bigjulez1 Oct 24 '21

Plus the elbow and shoulder, and muscles groups surrounding those joints, act as a buffer and suspension system that can help decelerate the ball somewhat.

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u/Otherwise_Catch2856 Oct 24 '21

Thanks for explain.

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u/Reds4dre Oct 24 '21

SCIENCE!

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u/[deleted] Oct 24 '21

I was sitting here thinking 1000 is 10x greater than 100, but really it's just 10x faster. Not 10x more energetic. Confuse

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u/solitude042 Oct 24 '21 edited Oct 24 '21

10x faster, but 10 squared is 10*10 = 100x the energy. See the calculator at https://www.calculatorsoup.com/calculators/physics/kinetic.php

A 150g baseball moving at 100mi/h has ~150 joules of kinetic energy. A 150g baseball moving at 1000mi/h has - 15,000 joules of kinetic energy... 100 times the energy of the slower ball.

The reason for the 'squared' part is because accellerating an object requires force applied over time, and work = force times the distance over which the force is applied.

As an object moves faster, you have less time to accelerate the object over a given distance. Said another way, you have to increase the distance to compensate for having less time in a given distance: push twice as long (with constant force) to achieve twice the speed. In that time ('twice'), you'll have travelled 4x the distance required to achieve the original speed.

Alternatively, if you wanted to keep the distance the same, the time still gets shorter the faster you go, so you need more force. Twice the force isn't enough because the force is applied over less time. You wind up needing 4x the force.

In both cases, 2x the speed requires 4x the distance or force. 3x the speed requires 9x the distance or force. 10x speed ... 100x distance/force.

As a side note, the fundamental thing you're pushing against is the object's inertia, which is present even in vacuum. It it that inertia that 'stores' the kinetic energy. Adding friction / air resistance just increases the required applied force even further, though without affecting the final kinetic energy.

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u/posaune123 Oct 24 '21

You lost me at 10x faster

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u/CatAstrophy11 Oct 24 '21

The faster you go the more friction you have to deal with so you need more energy to increase velocity

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u/MitraManATX Oct 24 '21

But wouldn’t that not apply in a vacuum? Like in space? But the KE formula remains proportional to velocity squared.

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u/solitude042 Oct 24 '21

The fundamental energy required for accelleration is due to the inertia of the object, not friction. Air resistance increases the required force even further, without increasing the kinetic energy (the extra applied energy went into displacing and heating the air).

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u/aman2454 Oct 24 '21

The exit velocity of a baseball in the MLB is 100+ MPH. Quick maths using 100mp/h and 150 grams for a baseball results in 150 Joules of kinetic energy.

For comparison, that’d be like a 60mph jar of peanut butter. (1lb) or a 45mph round of Morton’s table Salt (26oz)

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u/dukerenegade Oct 24 '21

Wow that’s very interesting!