During my family's recent Florida vacation, we spent several hours in a swimming pool so as to avoid the oppressive heat. My younger daughter kept asking me to throw her into the pool, and I couldn't turn her down. She loved getting into a cannonball position and having me throw her as far as I could while I was standing in the pool. Using a low-price digital camera's movie mode with a paltry 24 frames per second, my wife filmed me throwing my younger daughter into the water. My older daughter meant to serve as a height reference, but was too far from the plane of my younger daughter's trajectory to be a good length standard (I ended up using my own head!). The animated GIF below shows my child toss (click on the image for a larger view).
You can see a red trail connecting the data points (I marked my daughter's left shoulder). I marked the movie frames using a wonderful free video analysis program from Open Source Physics called Tracker (click here to get it).
So, could I compete in a professional child tosser event? Well, I launched my daughter at just over 5 mph (8 km/hr) at an angle of about 63 degrees from the horizontal. After a flight time of nearly 0.6 s, my daughter hit the water at a speed of about 11 mph (18 km/hr). She landed a horizontal distance of roughly 3.2 ft (0.98 m) from the point where I let go of her. Her entry into the water was about 75 degrees from the horizontal.
Many more goodies may be gleaned from video analysis. I could look at the small effect air resistance had on the trajectory. I could examine the force I needed to exert to get my daughter into flight. I could look at the splash dynamics. Lots of wonderful physics toys with which to play!
Professional child tossing probably won't catch on, but it's a lot of fun in a swimming pool with kids who love to fly through the air! That one may use a base-model digital camera and free software to turn fun in the pool into a first-year physics problem makes it all the more delightful.
So, could I compete in a professional child tosser event? Well, I launched my daughter at just over 5 mph (8 km/hr) at an angle of about 63 degrees from the horizontal. After a flight time of nearly 0.6 s, my daughter hit the water at a speed of about 11 mph (18 km/hr). She landed a horizontal distance of roughly 3.2 ft (0.98 m) from the point where I let go of her. Her entry into the water was about 75 degrees from the horizontal.
Many more goodies may be gleaned from video analysis. I could look at the small effect air resistance had on the trajectory. I could examine the force I needed to exert to get my daughter into flight. I could look at the splash dynamics. Lots of wonderful physics toys with which to play!
Professional child tossing probably won't catch on, but it's a lot of fun in a swimming pool with kids who love to fly through the air! That one may use a base-model digital camera and free software to turn fun in the pool into a first-year physics problem makes it all the more delightful.
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