1. Background

To introduce the concept of "Acceleration due to Gravity", drop two objects. Ask the students which object will reach the ground first (i.e. which will fall faster?). In reality, both objects will reach the ground at the same time since all objects accelerate at the same rate. The value of this acceleration is known as "g". (Note: We must ignore air resistance here. For example, if a feather and a brick are dropped at the same time, then the brick will reach the ground first since it is less susceptible to air resistance.)

2. Objective

	To analyse the motion of a freely falling object.
	To measure the acceleration due to gravity.
	To illustrate the operation of a photogate and its use in kinematics.
	To make use of datalogger hardware and software when conducting experiments.

3. Equipment List

	Datalogger interface connected to a PC
	Photogate
	Picket fence (students can make the picket fence by pasting several 5cm colour paper on a 30cm transparent plastic each 5cm apart with the same width as the plastic)