Estimate “g” Physics – Acceleration – Finding “g”

What is Gravity? Gravity is an accelerating force which always acts towards the centre of an object and is directly related to the amount of matter or mass that an object has. Newton's 3rd Law of uniformly accelerated motion and experimentation helps us understand how it effects mass. The law applies in this case to a falling object i.e. ball falling to the earth with a starting velocity; u = 0 ms -1. The only accelerating force is gravity and the time taken for the drop is t. s = ut+½at 2 s = 0+ ½ at 2 s = ½ gt 2 (2/g)s = t 2 From this we can work out g by graphing s against t 2. NB: in this case “g” is taken as having positive effect “s” or displacement is also positive.

Newton's 3 rd Law of Uniformly Accelerated Motion s = ut+½at 2 s = 0+ ½ at 2 s = - ½ gt 2 (2/g)s = t 2 Hence if w plot a line graph to fit the principle y = mx + c y = vertical axis (t 2 ) x = horizontal axis (s) m = gradient. (2/g) c=intercept (zero in this case or a systematic error) We can say 2/g = grad or 2/grad = g By taking the LOBF as drawn this experiment calculated g = ms -2  10 ms -2

Distance in m  (  0.002m) Time Taken in s (  s) Time Taken Squared in s 2 (  s 2 ) Small BallLarge BallSmall BallLarge Ball (2/g)s = t 2 Hence if we plot a line graph to fit the principle y = mx + c y = vertical axis (t 2 ) x = horizontal axis (s) m = gradient. (2/g) c=intercept (zero in this case or a systematic error) We can say 2/g = grad or 2/grad = g Plot the Points Precisely!