Physical Science: Forces & Energy
Lesson 3 of 3 7 min +45 XP

Projectiles & Gravity

Why 45° throws the farthest.

What you'll learn

  • Describe how gravity acts on a thrown object
  • Explain how launch angle affects range
  • Separate horizontal and vertical motion
The perfect throw

Throw a ball straight up and it goes high but not far; roll it flat and it goes far but low. Split the difference at 45° and it travels farthest, because that angle best shares the throw between height and distance against gravity's pull.

Two motions at once

Throw a ball and it does two things at the same time: it moves forward at a steady pace, and it rises then falls because gravity pulls it down. These two motions are independent — gravity does not care how fast you are going sideways. Together they trace a graceful curve called a parabola.

Simulation · Projectile motion

range = 40.8 m · peak height = 10.2 m

45° gives the longest throw — steeper trades distance for height. Gravity pulls the same either way.

Change the launch angle and speed. A low angle stays flat; a high angle goes up but not out. Around 45° sends it farthest.

The 45° sweet spot

Too flat and the ball hits the ground before it can travel; too steep and it wastes its speed climbing. Splitting the difference at 45° gives the longest range on level ground.

Lab · Paper-ball range test
  1. Throw a soft ball at a low angle (about 20°) and mark where it lands.
  2. Throw it again as close to 45° as you can, using the same effort.
  3. Finally throw it steeply (about 70°) with the same effort.
  4. Compare the three landing marks. Which angle went farthest?

What you should see: You confirmed with your own arm that a mid-range angle near 45° maximizes distance — the result the simulation predicts.

Knowledge Check

+10 XP / correct

1. On level ground with the same throwing speed, which launch angle travels farthest?

2. While a ball flies through the air (ignore air resistance), its horizontal speed…