Would any of these be correct? I'm not really sure what I'm doing but I tried....
(a) The y-axis is the period squared (T^2) of the pendulum in seconds which is the dependent variable, and the x-axis is the length of pendulum in metres, which is the independent variable.
The 6 points show the 6 different lengths of the pendulum which were changed so that an accurate calculation of g could be done through a line of best fit and deducing a gradient, by increasing the reliability of the data. The points (x,y) shows the period squared of the pendulum at each specific length.
The gradient shown is the acceleration due to gravity at the point in which the pendulum experiment was done. It is a straight line because g = 4pi^2 (l/T^2), and hence the y-axis is exponential. If it were simply T the graph shown should be a half-parabola. It is done like this to more accurately calculate the gradient and draw a line of best fit, which has been done.
(b) (i) Fc acting toward the centre of the circle, and Fg acting downward on the mass.
(ii) sqrt(Fc^2+Fg^2) (pythagoras’ theorem) -- resultant force
(c) I'm not really sure tbh, but after watching Chris Hadfield's videos, i'm just assuming the string and mass would hover?
The mass will continue to hover at the point where the astronaut let go of it. This happens because the mass is already in freefall and hence cannot ‘fall’ lower than the point it already is at without external force - which defeats the purpose of the experiment because the only force that should be acting on it is g. There is no upward force that would usually occur on Earth (supplied by the string) on it (because the mass cannot fall any lower) to allow it to move back and forth sideways for pendulum motion.
