Excel Spreadsheet Momentum and KE Calculator

[Ed Ashby]

#6032

I posted the following elsewhere in response to someone posting an incorrect momentum formula. It also has the directions for setting up you own Excel based momentum and KE calculator. So, if anyone is interested in setting up their own calculator, here’s the ‘formula cells’ in Excel spreadsheet format’; just “plug and play”.

Momentum = mass (in grains) multiplied by velocity if fps then divided by 225,218.

The figure 225,218 represents 7000 multiplied by 32.174. The 7000 converts the grains of arrow mass into pounds. 32.174 is the Gravitational Constant (Gc).

If you have an Excel Spreadsheet and you let block B:1 = arrow mass in grains and block B:2 = arrow velocity in feet per second then the formula to enter in block B:3 (in order for it to automatically calculate the momentum as you change either/or the arrow’s mass or velocity and return the answer in block B:3) is:

=Sum(B1*B2)/225218

Then you’ll have your own momentum calculator.

If you like you can set up the next block; block B4; to automatically calculate the arrow’s KE too. The formula to enter in block B4 in order for it to simultaneously calculate the KE is:

=Sum(0.5*B1)*(B2*B2)/225218

In the A column you can enter the labels for each field in Column B; ergo, block A:1 would be the lable “Enter arrow mass in grains”; A:2 would be “Enter arrow velocity in feet per second; A:3 would be “Arrow Momentum equals:”; and A:4 would be “Arrow Velocity equals:”

It’s a wise idea to lock the two formula cells; cells B:3 and B:4 to prevent accidentally entering something in them and wiping the formula out. Look in Excel’s “help” menu for info on how to lock the cells.

Ed

Added 2/10/10 Download the File from our Download Library.

[Ed Zachary]

#47641

Dr. Ashby and/or others, will this work with OpenOffice.Org 3.0?

[Ed Ashby]

#47674

I don’t know the formula formats for that program. It should be very similar, but the ‘formula format’ (the “=Sum” part of the equation) might be different.

Ed

[Ed Zachary]

#47701

Okay thank you, I will load it & see what happens.

[Ed Ashby]

#48233

Let us know if it works there too.

Ed

[Str8arrow]

#48774

Ed, why would someone want to know their KE?

[Ed Ashby]

#48859

Str8arrow wrote: Ed, why would someone want to know their KE?

1) It can tell us what KE is NOT useful for.

2) It’s what’s used to measure bow efficiency.

3) If you chronograph at the bow and again downrange it can tell us a lot about the flight efficiency of an arrow setup.

Those are the main reasons arrow KE can be a useful thing to know.

Ed

[Robin Conrads]

#49031

I have added this file to our Download Library. There is a link in Dr. Ashby’s first post on this thread, or you can use this link.

[Ed Zachary]

#62707

I got it to download to OpenOffice.Org,
seems to work okay, thanks again 😀

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