Abstract: When object with a magnetic is close to or away from the coil, pulse signal is induced in the coil due to the variation of magnetic flux. Digital storage oscilloscope is used to collect the pulse signal. The falling time of object can be obtained by analyzing the number of intervals of pulse signals. Thus, the value of acceleration of gravity can be gained and the motion law of free fall is verified.

Key words: digital storage oscilloscope, induced pulse signal, acceleration of gravity, free fall