Wednesday

A long strip of masking tape marks the launch line at the Field. Raven kneels beside the tape measure with the Field Log open.

"Same toss every time," she says. "Only the angle changes. That is what makes it fair."

Rocket swings his arm gently and lets the foam ball go low. It skims out and lands. Raven marks the spot.

He tosses medium, then steep. The steep ball hangs in the air so long that Nova drifts up to meet it.

"What do you notice about where they landed?" Raven asks.

"Medium went farthest, just like the text said," Rocket says. "But my steep one went farther than my flat one."

Nova hovers over the markers. "Measure before you decide," she says. "Three tosses each. Then compare."

Today you toss a foam ball at three launch angles: low, medium and steep. You toss three times at each angle.

You keep the toss speed as steady as you can. Only the angle changes. You measure every range and find the middle value.

Your medium toss probably went farthest. That matches the physics text: for a fixed speed, 45 degrees gives the greatest range.

Your low and steep tosses may not match each other. Your arm does not throw at exactly 15 and 75 degrees, and air pushes back on the ball.

NASA notes that on Earth a ball generates a moderate amount of drag, so a real flight is not strictly ballistic.

The hardest part of this lab is keeping the toss speed the same. If one toss felt harder, mark it in your log.

Changing only one thing at a time, the angle, is what makes a test fair. That is the rule week 12 is built on.

Careful field work. Tomorrow you read NASA's gravity table and ask how your toss would go on the Moon.