In this experiment, earth’s gravitational field strength was determined by using motion detector. The motion detector was used to measure and record a series of position and time of the track moving up and down along an inclined plane and plot the velocity-time and acceleration time graphs.
Where is the constant acceleration and is the displacement of the object at any given time? For an object under free fall, the initial velocity is always zero hence equation  can be modified as below to describe this motion;
Where is the height above the earth’s surface and is a constant acceleration due to the earth’s gravity? The acceleration can also be determined from the change in velocity over time as in this experiment;
The acceleration due to force of gravity was determined by timing the positions of the track up and down an inclined plane. The value obtained from the experiment was with uncertainty of which is less than the theoretical value. The small difference can be due to the air resistance and also due to the systematic error in the apparatus used since the values obtained were consistently lower than the theoretical