How would you answer c? I'm confused on the units as well.

Explanation:

The easiest way is to use Excel to graph the data and add a trendline.  Alternatively, you can use graph paper and a ruler and try to eyeball the best fit line.

The units of the axes are:

T = [s]

1/√k = [1/√(N/m)] = [√(m/N)] = [√(m / (kg m/s²))] = [s/√kg]

The equation for the period is T = (2π√m) (1/√k), so the slope of the line is 2π√m, and the units of the slope are √kg.  Using 4.30√kg as the slope, we can calculate the mass:

4.30√kg = 2π√m

0.684√kg = √m

m = 0.468 kg

If the actual mass is 0.500 kg, then the percent difference is:

|0.468 − 0.500| / (0.500) × 100% = 6.33%

close lines strong magnet less close weaker

d) physical means can be used to separate the components of air.