Rocket lobs the foam ball in a high arc over Raven's head. It drops gently onto the grass behind her.
"Steep when you want to clear something," he says. "Flat when you want to get there fast."
Raven turns the tape measure into a long jump line and leaps. "What do you notice? I made an arc too."
"You are a projectile," Rocket laughs. "A short one."
Nova hovers over the landing spot. "Every jump, kick and throw this term followed the same two motions."
Rocket nods. "Forward at a steady pace. Down from gravity. The only choices are speed and angle."
"Then let us read the week back," Raven says, opening the Field Log to Monday.
Athletes choose launch angles all the time. A steep lob clears a tall player and drops behind her.
A flat pass gets to a teammate quickly, because a low arc spends little time in the air.
A long jumper wants range, so she leaves the ground at a medium angle, not straight up.
A high jumper wants height, so he launches steeply and lands close to where he left the ground.
The physics text's rule explains all of it: the same speed goes farthest near 45 degrees and highest near 90.
| Sport moment | Goal | Launch angle |
|---|---|---|
| Lob over a tall player | height to clear, then drop | steep |
| Quick pass to a teammate | arrive fast | low and flat |
| Long jump | range | medium |
| High jump | height | steep |
NASA's flight page says a ball on Earth generates a moderate amount of drag, so its flight is not strictly ballistic.
Drag grows with speed. NASA explains that drag depends on the square of the velocity, so a fast ball feels much more air push.
That is why the best angle for range drops from 45 degrees to about 38 when air resistance counts.
In week 5 you saw a flat sheet of paper fall slower than a crumpled one. The same air is at work on every throw.
| Week review | True or false? |
|---|---|
| A projectile's forward motion and up and down motion are independent. | ? |
| Doubling the launch speed doubles the maximum height. | ? |
| Without air, 45 degrees gives the greatest range. | ? |
| The same toss would go farther on the Moon than on Earth. | ? |
| A ball tossed straight up has a long range. | ? |
Strong week, physicist. Tomorrow is Game Day: a family target toss, and next week you design a landing pad.