Projectile motion
Launch a ball and watch how the horizontal and vertical motions behave independently. Change the speed, angle and gravity.
- Independence of horizontal and vertical motion
- Acceleration due to gravity
- Range and maximum height
Range
49.4m
Max height
12.3m
Time of flight
3.17s
Time now
0.00s
Predict
Which launch angle gives the greatest range, with speed and gravity unchanged?
Experiment
- 1Set the angle to 30° and note the range, then try 60°. Compare the two.
- 2Sweep the angle from 5° to 85° and find where the range peaks.
- 3Drop gravity to 1.6 N/kg (the Moon) and see what happens to the flight time.
Explain
The horizontal and vertical motions are independent. Horizontally there is no force, so the horizontal velocity never changes. Vertically, gravity produces a constant downward acceleration, so the vertical velocity falls to zero at the top and then reverses.
That is why 30° and 60° give the same range: one trades flight time for horizontal speed exactly as much as the other gains it. 45° is the balance point.
This model ignores air resistance. In reality drag reduces both the range and the optimum angle.