Program Library


Let's experiment


Let's observe the relation between the distance y from the sensor to the basketball, which moves in a motion such as a pendulum, and the time x

Examples

We observe the swinging basketball hanging from the ceiling with the EA-100 Data Analyzer.
nswer the following questions.

Hang the basketball with a thread 50 cm long. Using the EA-100 Data Analyzer, observe and graph the results of each motion on the screen of the graphic calculator when the distances between the central or vertical position at which the pendulum will come to rest and the farthest positions away from it are 15 cm and 30 cm (half amplitude).
From the graph, find a relation between the amplitude and the period.

When the pendulum's length is 30 cm, 60 cm, or 90 cm (doubled, tripled, quadrupled), observe each motion using the EA-100 Data Analyzer and graph the results on the screen of the graphic calculator.

We obtained the results as follows.

Pendulum' length	30 cm	60 cm	90 cm
Period	t1 1.0993 s.	t2 1.5547 s.	t3 1.9041 s.

Calculate t2/t1 and t3/t1.
State what you find from these results.

Let the pendulum's length be y and the period be x, and we get the following formula.
y=1/4x^2
Confirm that this formula proves true.
According to this formula, the pendulum's length must be 1.56 m if we make the period to be 2.5 s.
Let's observe the motion when the pendulum's length is 1.56 m.