Newton's Law, balloon rockets and parachutes

We have been looking at the science of Newton's third law. We started this by making parachutes at our Tuesday group and carried on at home.

I liked these instructions for the parachutes and the website has lots of other activities too. We made the parachutes using tissue paper canopies. These were reinforced with tape at the corners then a hole was punched. We tied string through each hole, joined the strings in the middle and tied on a Lego man. The purpose of this was mainly to have fun, as the boys loved it, but also to show how the opposing force of air resistance inside the parachute acts against gravity to slow down the fall of the man.

We made our balloon rocket using these instructions. This was fantastic. The balloon would have travelled at least 3 times as far given unlimited space! The purpose of this is to show that the air rushing out creates the opposing force of thrust to force the balloon forwards, like a rocket is forced upwards.

As this had worked so well we decided to try a vertical launch. I tied the string from a stool to the ceiling light and this worked just as well, it's a shame we don't have higher ceilings! This is Harry counting down the launch.

After doing these activities, we also watched a video from Khan Academy about Newton's third law. Harry really enjoyed this, although it was quite advanced and he watched it through twice.