2012
Jun 14

Summer Science Projects: Physics

by Hannah Holt »

14 comments


Launch imagination into orbit with these fun physics activities!

#1) Balloon Rockets

  • Oblong balloons
  • Construction paper
  • Tape
  • Straws
  • Fishing line (we used a nylon chord, but fishing line would have worked better)

Use construction paper to build the rockets (make sure a balloon will fit inside). Cut the straw into a three inch tube and tape this to the back of the rocket. Thread the straw onto the fishing line. Fill the balloon with air and pinch (but don’t tie) the end. Place the balloon inside the rocket. Release and watch it fly.

Discussion Topic: Potential vs. Kinetic Energy

Two sentence explanation: When you blow up a balloon you pressurize it (like stretching a rubber band). When you let go of the balloon’s end, you change stored (or potential) energy into moving (or kinetic) energy.

Follow up questions: Could you design a balloon rocket that will go down the string AND come back? What other ways can you store energy (gravitational, elastic, chemical)?

#2) “POP” Bottle Projectile

  • a one liter plastic bottle
  • 1/4 cup baking soda
  • 3/4 cups vinegar
  • a cork (or a potato cut to fit the top of your bottle)
  • a funnel (to help pour the vinegar into the bottle)

Fill the plastic bottle with baking soda. Pour the vinegar into the bottle and quickly cork the bottle. In 2-3 seconds watch the cork fly. (Make sure it isn’t pointed at anyone.)

Discussion Topic: Gravity

Two sentence explanation: Gravity attracts (or pulls) everything on the surface of the earth downwards. The pull of earth’s gravity will eventually overcome the push the cork received from the bottle and pull it back to earth. (You could also test gravity by throwing a ball into the air, but where’s the fun in that?)

Follow up questions: Can you change how far the cork travels by switching the amounts of vinegar and baking soda? What if you changed the angle of the bottle from launch? What if you changed the substance of the cork to something like a wet paper wad?

Tips: It’s important that the cork have a tight fit. If you have a slow leak, the cork won’t pop. Also, you can use a different sized bottle than the one liter; however, you’ll have to play around with the vinegar and  baking soda ratios.

#3) Win a Quarter Trick

  • Four baseballs
  • A quarter
  • Masking tape
  • A measuring stick
  • A length of PVC pipe (for a cue stick)

This is an old pool hall trick, except we are doing it with baseballs and PVC pipe. If you can knock a quarter (or silver dollar) out of a circle you get to keep it, but the trick is it’s almost impossible.

Here’s the set up: create a two foot diameter circle using the masking tape, and place one baseball in the center of the circle. Balance a quarter on top of that baseball. Place the other baseballs outside the circle. Hit an outer baseball with the PVC pipe such that it knocks the ball in the middle. If the ball leaves the circle without hitting the other ball, try again. The goal is to knock the quarter out of the circle by “shooting pool.”

Discussion Topic: Newton’s First Law– Something won’t move unless something else pushes it.

Two sentence explanation: The quarter (most likely) won’t leave the circle because nothing hits it directly. When one ball collides with the other, the ground is knocked out from underneath the quarter, but there is no forward push. (Think of ripping a tablecloth out from under a bowl.)

Follow up questions: What would you have to do to knock the quarter out of the circle? Can you design any other games with balls and the two foot circle? What if you tried this set up with bouncy balls or soccer balls?

If you liked this post, you might also like Summer Science Projects: Biology, or Summer Science Projects: Chemistry.

Recap: For the past three weeks, our household has been on a science quest. We’ve learned many things. Like, oblong carnival balloons are a riot to have around the house.

However, more importantly, I’ve seen a big difference in the inquisitiveness of my boys (ages four and six). After the first couple of experiments, they started designing their own. Even within the tailored projects here, I was impressed by the range of creativity they expressed. I plan to run at least one science related experiment a week with them; however, I probably won’t post these here. If you’d like to keep up with our summer science projects, follow my Kid Craft Ideas page on Pinterest.


  1. Susanna Leonard Hill

    These are all so clever and fun! They make physics seem so much less intimidating than in high school! :)

    • Hannah Holt

      Physics get a bad rap sometimes. There are so many fun ways to explore Newtonian physics. Glad you enjoyed.

  2. Mom Holt

    Like the balloon rocket, these experiments and discussion following seems to have launched your kids into exploration on their own. How wonderful that is! And best of all……it’s FUN!

  3. Eric VanRaepenbusch

    Great ideas! I love the balloon rocket race! My kids enjoyed the videos too!

    • Hannah Holt

      Thanks. We enjoy the book trailers you put together!

  4. Heather Newman

    You know you’ve hit upon something great when it sparks an ongoing interest! Thank you for sharing the videos, the expression on your son’s face after the cork popped was priceless.

    • Hannah Holt

      Thanks Heather! Hope you and your boys are enjoying the summer.

  5. Kirsten

    We did the balloon rocket activity at science club one time. It was so much fun. Love those squeals of delight!

    • Hannah Holt

      Thanks, Kirsten. Your science club sounds awesome!

  6. Joanna

    This is a fabulous post, Hannah. I learn so much from your blog. i want to come and sit in on your activities with the kids. The balloon rocket race is uber cool!

    • Hannah Holt

      Thanks, Joanna!

  7. Stacy S. Jensen

    I never thought I would read “fun physics activities” and believe. Nice videos too.

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