Kinetic Energy: What It Is, Why It's Important, & How To Calculate It | Bowhunt 101

[@pasclo85]

As bowhunters I feel we should focus about what KE our arrows have down range at the point of impact. Not when it leaves the bow. In flight, drag will cause the arrow to loose velocity (mass remains constant). I think that's where heavier arrows have an advantage over lighter ones, sure they fly slower, but don't,t loose as much speed in flight and have greater mass.

[@RoweClean]

Weight for quieting everything down is the biggest advantage! And it makes a huge difference! The most important thing on an arrow setup is a razor sharp broadhead. In the end, the kill factor is laceration.

[@bowhuntordie]

The most important thing on the arrow is certainly the broadhead. However, the most important thing in bowhunting is accuracy. Gotta hit them in the right spot.

[@RoweClean]

@@bowhuntordie dang it I went off am got one upped after one upping. The advantage of the NAP is that cutting diameter makes up for some of my personal accuracy mishaps in the moment!

[@RoweClean]

@@bowhuntordie kzbin.info/www/bejne/iYS5koufd9aXorM

[@SellsZac]

I think you want to be pretty fast (260fps+) and pretty heavy (450+) and you'll be alright in almost every application. I currently have a Vertix with at 29.5" DL, 68lb dW, 500grain arrows and 275 fps average. Shooting a 125g fixed blade cut on contact. If you're mainly hunting white tail, even the shoulderblade is pretty punchable with a serious setup.

[@brandonmcdowell6537]

I have a 25 .5 " draw length and 60lbs draw weight and I shoot Easton fmj's and 125 grain fixed blade broadheads

[@irwinoutdoors3636]

This is a good video and has many good points , but the statement at 7:58 where it’s said that the weight increases the kinetic energy quicker than the velocity is actually incorrect. The formula for kinetic energy is k= 1/2 mv^2. This means that the velocity actually increases the kinetic energy quicker. This can be proved mathematically very quickly. Double the mass :1/2(2) (1)^2 = 1 Double the velocity: 1/2 (1) (2)^2= 2 This shows that velocity has a greater effect on kinetic Energy.

[@Woodsyone]

Blah blah blah. Grab your bow and go hunting , jeez. This high tech crap has no woodcraft wisdom in it whatsoever. There's a reason bowhunters after dangerous game beef up their arrows. It enables their arrows to drive through heavy muscle and or bone much, much more effectively than the lighter stuff that flies so fast. Stick with the old time wisdom, Papa Bear knew what he was talking about. Rely on your woodcraft skills, not store bought confidence instilled by an eager salesman........

[@bowhuntordie]

Thanks for the information we'll have to do some research on this. I'll have to ask Justin, but I think the idea he was trying to get across was that it was more efficient/easier to increase the mass, than to try to increase velocity. What do you think?

[@irwinoutdoors3636]

Yes, I think that he was trying to make a point, and meant one thing and said something else. This is easy to do and understandable, but I just wanted to bring it to light so that people would have the right information. I do agree that many times it is better for someone to increase the weight of their arrow instead of increasing it’s speed. This is often times simpler to change as well as the fact that having too heavy of a draw weight is a bad thing. All of these factors vary for different setups and different people. I believe that the most important thing is to balance the two in a way that makes the most sense for a particular person.

[@NoName-bg2om]

Yes it is true speed increases kinetic energy more, but mass increases momentum more. I always like to look at the kinetic energy/momentum numbers but I don't setup my arrows specifically to some number of something. I prefer a more practical approach, good velocity with good arrow weight. For example my 70lb Matthews Halon 32 with 29.5 DL shoots my 475 grain arrow at 291 Fps, that's about 89 Ke. For me that's a perfect mix of arrow weight and velocity.

[@thorwaldjohanson2526]

​@@NoName-bg2ommass increases momentum the same as velocity. However, I think why increasing the mass is easy and effective is the following: the energy stored in the limbs when fully drawn does not all go into accelerating the arrow. It also goes into accelerating the string and the limbs plus some friction. To illustrate this with numbers I pulled out of my ass: let's say you have a 400g arrow, but the sting and limbs are an extra 600g which have to be accelerated. So 1000g overall. Now you increase the arrow weight by 20% to 500g. The overall weight of mass to be accelerated only increased to 1100g, a 10% increase. So now a larger portion of the energy stored in the limbs gets used to accelerate the arrow. I would love to actuallyeasure this and find the sweet point... Yes im a nerd :D

[@kylecarpenter40]

32” draw length and 68# draw... I wish there was a conversion without a chronograph so you know if it’s beneficial or can relax the weight, but knowing every bow is different. Looks like a trip to the archery shop!

[@ApexPredatorOutdoors]

The way I look at it kinetic energy is the factor important for getting the arrow to the animal and shooting flat, momentum is more important when it comes to driving through that animal with a broadhead. They are two similar things that are driven by different factors. Kinetic energy is more speed dependent and momentum is more weight dependent.

[@shawnkelsey6224]

I’m trying to get my brother to Bowhunt with me . I told him how much fun it is and how much of a challenge it is . My question is for a new bow hunter , What is the best bow to start with ? My bow is a Hoyt Spider and I’m dialed in at 35 yards . Just asking for my brother if anyone has an idea just let me know thank you ! Also love your content ! Thank you and Bow Hunt or Die ! Good luck to everyone on the upcoming season!

[@Woodsyone]

Your enthusiasm for bowhunting is great. Stick with it, the struggle IS the reward. One bit of advice though. Relying too much on technology and gadgets to achieve whatever goal you have might indeed make achieving that goal "easier", maybe not, but the most satisfying moments in life never come easy. Keep that in mind. Knowledge and lessons learned through experience in the woods are much more reliable tools........

[@bowhuntordie]

That depends on what kind of budget he's working with. You can still find really great bows that are a few years old, but still plenty efficient at about half the price of a new bow. And there are also great options for a new bow that can be around $400-$600.

[@richarddean3154]

Wow! Your bow is really flinging those arrows well. Thanks for the great and informative video.

[@michaelmendez8984]

I’m a 27 in draw with 75 pound mods. Mathews v3. I shoot a 429 grain arrow 340 spine and around 290 FPS. I’m getting around 80 pounds of kinetic energy. When I start adding weight to my arrow and the speed decreases so does the kinetic energy. Guess that’s how it is with a shorter draw length! Lol

[@Patient_Xer0]

(humbly new to hunting) basically, i have 2 arrows, mossy oaks and carbon express terminators, the oaks are 29inch 8.9 gpi, the expresses are 30 inch 11.3 gpi, i use 100g field tips and broadheads, im trying to decide if i should use the new terminators i got, take an inch off of the terminators and redo the inserts, add 5 more pounds to accommodate the higher gpi on the terminators, or simply go back to my mossy oaks, i want as much speed as possible, but without sacrificing kinetic energy, as i want clean pass throughs ( though for whitetail, isnt 53.2 enough for a passthrough anyway with a sharp fixed broadhead?) i just want to be efficient as possible, while getting the arrow to vitals in a timely manner without having to worry about wounding because of a string jump and a slightly slow arrow, any helpful constructive feedbacks or recommendations are all welcome and thank you kindly in advance. (Currently I shoot a Bear G2 Cruzer, don't know which setup to go between, i shoot a 55ib bow at 28inch draw length, the arrow stats are as follows;) Current setup: CE Terminators, .350 Spine, 30 Inch (55ib) (28Inch DL) Arrow Weight: 439g Arrow speed: 233.67fps Momentum: 2.026ns Kinetic Energy: 53.21 ft/ib Old Setup: Mossy oak Arrows, .350 Spine, 29inch (55ib) (28Inch DL) Arrow Weight: 353.3 Arrow speed: 262.6 (way Faster!) Momentum :1.826 Kinetic Energy: 53.92 Prospect (first arrow with an inch taken off) CE Terminators, .350 Spine, 29inch (55ib) (28Inch DL) Weight :427.7g Arrow Speed: 237.43 Momentum: 2.025 Kinetic energy: 53.53 2nd Option? Setup: (same Arrow as first but add 5ibs draw weight to my bow) (60ib) (28Inch DL) Weight: 439g Arrow Speed: 242 Momentum: 2.098 Kinetic energy: 57.08

[@richardofoz2167]

Kill them with stats, man. Show this list to your prey and watch them fall down dead.

[@ddm650]

What is the model of that bow u were using it?

[@bowhuntordie]

That is a Mathews VXR

[@deonhudson8719]

Thank you for the lesson

[@waynehumphrey8910]

Good video I like how to videos bow set ups food plots also waiting for some trail camera pictures

[@laicheekien7350]

what is the arrow spine for your setup？

[@bowhuntordie]

340 Spine

[@laicheekien7350]

Thank for your information

[@dillonbutler6098]

Thanks for the tip Big dawg 🤙

[@stevenmansfield4644]

That helps understand it better

[@justinlong3621]

Such awesome advice on here! Thanks.

[@chrismacomber9727]

Cool tec tip guys

[@Woodsyone]

It's nice to see someone who is not afraid to recommend heavier arrows over those puny, zippy things. Old time wisdom is finally making a comeback in the bowhunting world! Now, about all this electronic crap strapped to your bows....,.. next time.lol

[@nswfftp]

You guys did great videos on “FOC” and “Kinetic Energy” now do one on “Momentum”. Break down SLUGS for us mouth-breathers.

[@richardofoz2167]

Ever heard of Google?

[@randymarker9657]

To gain more energy u have to draw more pounds my 406 grain arrows at 280 have 71 pounds of energy at 26.5 lenght arrows

[@jerrycox5700]

Awesome video thanks brother

[@grahamflowers]

There is no kinetic energy in a moving mass there is force Mv squared kinetic energy is the energy of consistent work from a consistent force regards Graham Flowers MEng

[@kotkrinik]

You are very wrong. KE = 1/2*m*v². This is obvious, that v² is more important than m, because v is square.

[@richardofoz2167]

Your discussion of kinetic energy overlooks the fact that KE is calculated using the speed SQUARED, so KE is much more sensitive to changes in speed than to changes in weight. Also, bowhunters will tend to use their bow's advertised bow speed rather than its actual speed as measured by a chronometer. And even if they use a chronometer to determine the actual speed, it will be set quite close to the bow, where the archer is guaranteed to avoid hitting the chronometer itself. In either case, the arrow's speed will be considerably greater than its speed at the target, which is all that counts. So, I think your guidance here is quite misleading. Anyone familiar with firearm ballistics will have published tables showing projectile velocity at various down range distances, and will be well aware of how quickly velocity drops off. This, of course, affects both trajectory and downrange energy, and it's the downrange energy which must be taken into account when assessing the adequacy of any bow-arrow combination. Furthermore, you haven't mentioned at all what is probably the most important factor to consider - shot placement. A poorly placed shot, which is all too likely to result when the archer focuses primarily on factors like draw weight and kinetic energy, will NOT achieve a quick and humane kill. On the other hand, a well placed shot with equipment which on paper may seem inadequate, is much more likely to achieve success for the hunter in an ethical manner. Given the very slow velocities in archery compared with firearms, shot placement is extraordinarily dependent on reliable range estimation. I think you would have done much better to encourage hunters to practice their range estimating skills using a reliable laser rangefinder. Don't kid yourself that you can always use the rangefinder when hunting. The time taken to do so is time you will spend watching your prey bounding into the next county. Don't make the mistake of encouraging hunters to focus on aspects of "power". Far more important is having a bow you can handle easily and quietly, and being able to quickly and reliably estimate your range to target. Finally, let's not overlook the importance of keeping your broadheads razor sharp. If you're hoping to penetrate through hide and solid muscle on an animal that is fitter than any human athlete you've ever seen, blades that your buddy sharpened last season before they spent months bouncing around in your hunting kit are NOT going to cut it, either figuratively or literally.

[@african7498]

Momentum is a better metric than kinetic energy at the muzzle - the force to keep moving

[@richardofoz2167]

What if my bow has no muzzle?

[@whatupted3741]

Not true you don’t need 60 or 70 # many Hunters use 45 # and use a traditional bow and harvest many game animals look up the history Fred bear the father of bow hunting

[@russellshealy9395]

Professor BHOD

[@christopherp.hitchens3902]

Question: How much intellectual “energy” does it require to shoot an arrow into an animal that is quietly minding its own business? Is there such a thing as less-than-zero “Failed-Male” energy? You know…as in a Trump supporter? Thank you!

[@richardofoz2167]

Don't ever stop being a jerk, man. It's what makes everyone love you.