Quick Question about the acceleration formula

AI Thread Summary
The discussion focuses on the acceleration formula a=F*k and the units for the constant k. It clarifies that acceleration (a) is measured in meters per second squared (m/s²) and force (F) in Newtons (N), which can be expressed as kg·m/s². Through dimensional analysis, participants explain that k must have units that allow the equation to balance, leading to the conclusion that k is not simply in Newtons. The conversation also touches on the relationship between k and Hooke's Law, indicating that k represents a spring constant rather than force. Understanding these unit relationships is essential for solving related physics problems.
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When you use the formula a=F*k, what are the units of k (such as N, m, s, that kind of thing). I need to know for a problem I have to do for homework, so if you could clear it up for me it would help!
 
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oooo said:
When you use the formula a=F*k, what are the units of k (such as N, m, s, that kind of thing). I need to know for a problem I have to do for homework, so if you could clear it up for me it would help!
Think about it this way, a is ms^-2, and F is N. By the definition of 1 N, 1 N = 1 kg ms^-2
So,
ms^-2 = (X)* kg ms^-2
Where X is the unknown unit of k...
In this case, treat each unit as an algebraic quantity, re-arrange for X and you'll know what the units are... (Dimensional analysis...)

You may ask why I left the numbers out... Well, even if you have 3 N on one side with a being 1 ms^-2 on the other side, we really don't care what the value of k IS in this case, just what kind of a unit it represents...
So yeah.
 
Well, all that I know is that in Newton's Second Law, F=m*a, which is the same as a=F/m. Then, looking at a similar formula using k, I see that a=k/m. Thus I thought that k=F and thus k was in units of Newtons. But, for some reason I was wrong. Am I on the right track?
 
Actually, I think you're referring to "Hooke's Law".
In that case, F = kx... = ma, or a = kx/m... not k/m...
 
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