Solve Mass of a String Problem | Physics Homework Help

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A 1.50-meter-long string under 30.0 N of tension allows a pulse to travel its length in 50.0 ms, resulting in a calculated pulse velocity of 30 m/s. Using the formula for the string's mass-to-length ratio, the calculation yields a ratio of 0.033 kg/m. This ratio is then used to find the mass of the string, resulting in approximately 0.05 kg. The confusion arises from the need to express the final answer in grams, leading to a clarification that 0.05 kg equals 50 grams. The discussion emphasizes the importance of unit conversion in physics problems.
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Homework Statement


A 1.50-m-long string is under 30.0 N of tension. A pulse travels the length of the string in 50.0 ms.

Homework Equations



v of string = sq rt of (Tension of string/ string's mass-to-length ratio)

string's mass to length ratio= m/L

The Attempt at a Solution



So, the pulse takes 50.0 ms to travel through 1.5 m of string. So, the velocity of the pulse is 1.5 m/.050 s.

V= 1.5/.050 = 30 m/s

Now that I know the velocity, I can use the V of string equation.

V^{2}= T/\mu
\mu= T/V^{2}
\mu= 30.0N/ (30m/s)^{2}
\mu=.033

\mu=m/L
\mu*L=m
.033*1.5=m
m=.049995 or .05 g

However, master physics disagrees with this answer. What am I doing incorrectly?
 
Last edited:
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The answer should be in kilograms not grams.
 
Actually, the unit they want mass in is g. Sorry. Forgot to put that in there.
 
I was not clear explaining what I meant. The answer that you got, 0.05 is in kilograms. You need to convert that to grams. Did you enter 0.05?
 
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