HallsofIvy said:It isn't "1/3 inches"- it is 1/3 feet. What are the units for k? Since k times a distance is equal to a force, k must have units of "force divided by distance". If k has units of "pounds per inch" then "4 inches" would be correct. But if k has units of "pounds per foot" then 4/12= 1/3 feet is correct..
... yah: I was going to say: why did you write down 1/3 if you don't know what it means?24 = k*(1/3)
why is it 1/3 inches and not 4 inches?
Comes from the problem statement ... translate those math expressions into English sentences and see. x(0) is x(t) at t=0, and x'(0) is the 1st derivative of x(t) at t=0.Also, the answer key has initial conditions. x(0) = -1/4 , x'(0) = 0.
Yes, I just realized that 1/4 foot is 3 inches. These units are confusing me. I actually did have my work right but the answer key made me think otherwise.Simon Bridge said:... yah: I was going to say: why did you write down 1/3 if you don't know what it means?
If you want to use 4", why not use 4"? It's allowed.
If it's part of an answer key, then it's someone elses work: why are you writing down someone elses work? Do it the way you'd do it, and then compare results.
I see this is a math course - in physics, as you just found out, numbers have units to give them physical meaning. You'll have seen this in other examples by now - but it does take a bit of practice to get used to.
Comes from the problem statement ... translate those math expressions into English sentences and see. x(0) is x(t) at t=0, and x'(0) is the 1st derivative of x(t) at t=0.
Simon Bridge said:The initial problem statement did not include a question - what was the wording of the task?
If you are not told the units, you can use what you like as long you specify at the start.
If you are self-marking it can be tricky, but your teacher appears to have been consistent in the question to use the f-p-s standard units.
http://en.wikipedia.org/wiki/Foot–pound–second_system
Is it possible that your teacher expects you to use this standard when units are not specified - just like others prefer SI (m-k-s) units by default?
The value of s = 1/3 is a commonly used approximation for the number 0.3333 which represents one third. This value is often used in mathematical calculations due to its simplicity and convenience.
No, the value of s = 1/3 is an approximation and not an exact value. It is impossible to express one third as a decimal without rounding, as it is a repeating decimal (0.333333...).
The value of s = 1/3 is commonly used in mathematics because it is a simple and easy to remember approximation for one third. It is also used in many equations and formulas where one third is a common factor.
Yes, s = 1/3 is also commonly used to approximate other numbers that are close to one third, such as 0.333, 0.3333, or 0.33333. It is also used to approximate fractions that are close to one third, such as 2/6, 3/9, or 4/12.
No, the value of s = 1/3 should only be used as an approximation and not for exact calculations. It may lead to errors in more complex calculations and it is always recommended to use the exact value of one third (1/3) if possible.