Year 5 – Earth and Space Experiment

Today, in year 5 we have been investigating the time it takes for planets to orbit the Sun. The children have been exploring patterns in the time it takes for planets at different distances to orbit the Sun. We used a ball and string model, a stopwatch and a ruler to measure the different lengths of the string.

The children worked in teams of three or four, each with a particular role:

• The Spinner, measured the string at different lengths and rotated the ball
• The Counter, said when the stopwatch should start and finish, as well as counting 10 orbits of the ball.
• The Timer, started and stopped the stopwatch
• The Recorder, recorded the data in a table for the group.

To start, the spinner measured the length of the string attached to the ball to 20cm. Then, the Spinner held the string at the 20cm mark and steadily rotated the ball.  Once rotating, the Counter shouted ‘start’ to indicate to the Timer they should start the stopwatch. The Counter counts 10 full orbits and shouts ‘stop’ to tell the Timer to stop the stopwatch. The Recorder then recorded this.

They then changed roles between tests. The team then tested the 20cm length 3 times and then repeated the tests with 40cm, 60cm, 80cm and 100cm lengths of string to the attached ball.

To conclude, we found out the longer the string, the bigger the circle the ball has to travel in – it has to travel further and so it takes longer. Therefore, the longer the string the longer the time, the shorter the string the shorter the time. Our data can be used to model what happened in the solar system – planets further from the Sun take longer to orbit and those closest take less time. Mercury takes three Earth months whereas Uranus takes 1009 Earth months to orbit.

A fantastic investigation year 5 well done!