We started off our February 23rd program with some introductions since we had so many new faces! And then we quickly turned our attention to the theme for the day’s program: Forces. The G3 scientists learned that there are different kinds of forces. For example, a push force could be something like one person pushing another person backwards. An example of a pull force could be gravity itself, and how gravity pulls objects downward toward the earth’s surface. Forces have the ability to change the speed or even the direction of an object.
As inspiration for the day’s activities, Nicole also showed our scientists a fascinating video about Joseph Kittinger . In 1960, not only did he become the first man in space, but he also – to this day – holds the world record for the longest free-fall parachute jump! Wearing a special pressurized suit, he rapidly climbed skyward in a helium balloon – so high that he broke through the troposphere and could look back on the earth from the darkness of space. And then, he did the unthinkable – he jumped! And then he fell – at the speed of sound – back towards the earth. Thanks to the parachute, his speed significantly slowed down and within 15 minutes of jumping he had landed safely back on earth.
When somebody jumps out of a plane and parachutes to the ground, two key push and pull forces are in action. Gravity rapidly pulls the person toward the ground. Then the parachute helps to provide a crucial push force that slows a person’s descent and keeps them from smacking into the ground. How is this push force created? Air collects under the parachute and provides resistance, or drag, that essentially pushes back against the “pull” of gravity and makes a person fall at a much slower and safer rate to the ground.
To test both push and pull forces, the task of the day for our G3 scientists was to create and release their very own parachutes! An example of a simple parachute design can be found on the website for PBS’s program FETCH (though there are many similar experiment instructions to be found online). Our materials for the parachutes were simple enough:
- 10″ x 10″ squares cut from plastic garbage bags
- 10″ x 10″ squares cut from tissue paper
- 10″ x 10″ squares cut from cloth
- 8″ x 8″ squares cut from cloth
- paperclips (our “human beings”)
The real challenge was figuring out which material made for the best parachute (in other words, the slowest drop to the ground). Each G3 scientist was given the opportunity to launch their parachutes by climbing a tall ladder (always under the watchful eye of Nicole’s fellow librarian, Kelley). Nicole timed all launches with her handy stop watch, and all scientists had pieces of paper to record their various times on. Early in our testing, it seemed that the garbage bag parachutes were winning with the longest and gentlest falls to the ground. But as soon as the tissue paper parachutes came into the mix, it was clear that tissue paper was the winner, hands down.
At the start of the program, we timed a paperclip with no parachute falling from the top of the ladder – it fell to the ground in less than 0.5 seconds. Our best parachute of the day was a tissue paper parachute that took close to 5.5 seconds to hit the ground! When all materials had been tested, G3 scientists had complete creative control to design their own versions of parachutes to test. We had some very interesting designs paired with some very interesting names. Some great examples of the day’s creativity were “Dead Bird Falling” and the follow-up design “Dead Bird Having Babies”; a four-person parachute; the kite parachute; a “sticky situation”; and the “plane-chute” (a combination of a paper airplane and a parachute!).
As always, we closed the program with a quick recap on how the experiment went and a brief show-and-tell of all of the terrific unique parachutes our scientists had created and tested. Who knows what fantastic science we’ll see in the month of March. Stay tuned!…