InterActions in Physical Science

data tables Five students in the class were asked to draw a conclusion from the class data table and to support their conclusions with reasons. The conclusions and reasons are presented on this page and the next page. The first student supported her conclusion with a good reason, so her conclusion is valid. The next four students, however, supported their conclusions with poor reasons. Their conclusions are not valid.

On your own, read all the conclusions and supporting reasons. Think about why the reason provided by the first student is considered good. Then think about why the reasons provided by the last four students are considered to be poor

Student providing good supporting reason
(Conclusion is valid.)

Student A-Conclusion

I conclude that as the length of a pendulum increases, the time it takes to swing back and forth 10 times also increases.

Reason

As can be seen from the class data table best values, as the length of the pendulum increases from 50 cm to 60 cm to 70 cm to 80 cm, the time to make 10 swings increases from 14.0 s to 15.2 s to 16.9 s to 18.0 s. Taking into account the uncertainties, all these values are true increases.

Students providing poor supporting reasons
(Conclusions are not valid.)

Student B-Conclusion

I conclude there is no relationship between the length of a pendulum and the time it takes to swing back and forth 10 times.