Hi,every one. Yesterday,we did a experiment. This experiment named Pendulum Experiment.

First,we made a pendulum with:String,ring shaped rubbers and sissors.

Then,the experiment is ecchion.

1.we tied the rubbers onto a string to made a pendulum.Next,we marked lengths of 10cm,20cm,30cm ,40cm and 50cm on the string with the marker pen. then we stuck the string to the corner of a desk using the sticky tape.

2.the tiner was set for 30 seconds. One person pulled the bob of the pendulurn to the side. We released the pendulum and started the timer at the same time. We counted how many times the pendulumswung in 30s.

Results

length:10cm 20cm 30cm 40cm 50cm

Swings:42 32 26 23 20

Size :1/4stringlength 1/2 string length 3/4 string length

Swings:20 20 20

weight: 1 rubber 2 rubbers 3 rubbers

swings: 20 21 20

Conclusion

We found that some things change the speed of a pendulum,and some things don't change it.

The leng of the string change the speed of the pendulum. When the string was longer the pendulum swung slwer.

The size of the swing did not change the speed of the pendulum.

The weight of the bob did not change the speed of the pendulum.