In 1/2mv^2, is m grams & v ft per second?

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In the formula E = 1/2 mv^2, mass (m) should be in kilograms and velocity (v) in meters per second to calculate energy in joules. The discussion focuses on calculating the heat energy (in BTU) from bullet impacts, emphasizing the importance of using MKS units for accuracy. It is noted that 1 BTU equals 1055 joules, allowing for conversion if needed. The consensus suggests avoiding British units for simplicity. Accurate unit conversion is essential for precise energy calculations.
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I understand that the energy is in joules (?), but unsure of mass and velocity formats. I am trying to calculate the energy of an impact. Specifically, the heat energy (btu) resulting from various bullet impacts. Feel free to ask further questions if you need to know something else to answer my question.

Thank you
 
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To get an answer in joules, m must be measured in kilograms, and v in meters per second.
 
skizbok said:
I understand that the energy is in joules (?), but unsure of mass and velocity formats. I am trying to calculate the energy of an impact. Specifically, the heat energy (btu) resulting from various bullet impacts. Feel free to ask further questions if you need to know something else to answer my question.

Thank you
The energy of a bullet of mass m traveling at speed v is E = \frac{1}{2}mv^2

Assuming that this is all converted to heat on impact, the heat produced is:

Q = E = \frac{1}{2}mv^2

Life is too short to use British units. Put the units in MKS (metres, kg, sec.) and then convert at the end if you want Btu. 1 Btu = 1055 J.

AM
 
Thank you. PS - I like your thoughts on British units :)
 
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