You are also provided with a very thin and light string, the mass $($and$,$ correspondingly, mass

density$)$ which may be more difficult to directly measure using the available balances in the lab. This

time, there is no need to measure

$0$ directly using a digital balance.

$$ Set up the equipment as in Exercise $1.$ In this exercise, we will use only one mass on the hanger

$(100$ g$,$ say$)$ and one particular mode only $($n$=2$ may be the easiest$).$ Don$$t repeat for other values

of F$.$

$$ Follow the same procedure as in Exercise $1$: Add a certain mass $(100$ g$,$ say$)$ to the weight hanger.

Vary the length of the string and find the frequency of your chosen mode at as many different

lengths as possible, just as in Exercise $1.$

$$ Determine

$$ for the provided string the same way you did in Exercise $1.$

why would we not measure u in exercise $2?$ a$)$ the linear mass is not constant, b$)$ we already measure u in exercise $1,$ c$)$ the string is too light for an accurate reading on the balance, d$)$ we assume the string is massless