Some 250 of the best high school physics students in Iowa are taking part in the state finals of the Physics Olympics today at Drake University in Des Moines. Events include: building toothpick bridges, the soda straw arm and car catapults. Drake science education professor Jack Gerlovich says the student-powered water heater is exactly what it sounds like.Teams are given a measured amount of water and have five minutes to raise its temperature using only human power. The team with the warmest water wins. Gerlovich says another event called the catapult car involves creating a small vehicle that has to travel a prescribed distance, then shoot a projectile.Students create a small catapult that will travel between two and three meters and carry a ping-pong ball to be launched at a target at the end of the course some five meters out. The catapult that sticks closest to the course and lands the ball closest to the target wins. Students from 30 Iowa school districts are taking part in the events. Gerlovich says the goal of the Physics Olympics is two-fold — first, to allow the students to have fun, the second is to apply physics principals to real life problems.The competition involves high school students who won regional contests earlier this year and starts at 8 AM. The contest is free and open to the public. Winners will be recognized at an awards ceremony this afternoon. Other events include: Falling mass-powered cars: students raise a one-thousand-gram weight 50 centimeters above a toy car to create energy that, when released, will move the car. The farthest-moving car wins. Toothpick bridges: students use toothpicks and Elmer’s glue to build bridges. The bridge that flexes least under weight is the winner. Soda straw arm: teams of two receive 20 jumbo plastic straws, 20 straight pins and 30 minutes to build an “arm” that will hold weight. The longest “arm” that can hold 100 grams for ten seconds wins.