[填空题]
1.A student investigae.q:4ogcmgm9i tu p6*tes standing waves in strings. A stridxbtx *5 e/ fyv;p1v0ynf sf9-+mn/vxng is connected to an oscillator where a function generator can adjust the frequency. The other end of the string passes through a pulley and supports vm5f9 dxfx*v s0;vxnt - y/f+/pyb n1ea mass.
The student varied the mass $m$ and recorded the values for frequency $f$ for which the first harmonic wass visible on the string. The following graph shows the recorded data.
The uncertainty of the mass is negligible.
1.Draw the line of best fit for the plotted data on the graph.
2.By referring to the plotted data, explain why it cannot be stated that frequency is directly proportional to mass.
3.Use the graph to determine the value for $f$ with its absolute uncertainty for for m=1.0kg. $Hz$
2.The theory suggests that
$f^2=km$
where k is a constant.
The variation of $f^2$ with m is seen on the graph below.
1.Show that the absolute uncertainty of $f^2$ is$\pm0.01Hz^2$ for m=1.0kg. $kHz^2$
2.The absolute uncertainty of $f^2$ is 0.03$kHz^2$ for m=0.25 kg. Construct error bars for $f^2$ when m=0.25kg and m=1.00kg.
3.State and explain whether the theory is supported by data or not.
3.Determine the unit of k, in fundamental SI units. $kg^{-1}$
