Horizontal motion at constant speed combined with vertical motion under gravity.
A projectile has constant horizontal velocity and vertical acceleration -g. Range R=v²sin2θ/g, maximum height H=v²sin²θ/(2g), and time of flight T=2v sinθ/g. Air drag reduces range and lowers optimum angle.
A ball at 20 m/s and 30° travels about 35.3 m.
Projectile motion is the classic two-dimensional case, and it is used in ballistics, sports and the sizing of spray or jet systems.
Horizontal motion at constant speed combined with vertical motion under gravity.
Projectile motion is the classic two-dimensional case, and it is used in ballistics, sports and the sizing of spray or jet systems.
Forty-five degrees, when air resistance is ignored. Real drag shifts the best angle lower.
Gravity acts only vertically in the simple model, so there is no horizontal force to change the horizontal velocity.
Typical applications include estimating the range of a water jet from a fire hose, predicting where a dropped package lands from an aircraft and sizing the launch angle for a ball-throwing robot.
Study "Uniform acceleration equations" first (topic 22 of 106 in Engineering Mechanics). It covers the groundwork this topic builds on.
Maximum range at 45° without drag. Horizontal and vertical motions are independent. Trajectory is a parabola.
A ball at 20 m/s and 30° travels about 35.3 m.
The next topic is "Relative motion", which builds directly on this one.
It is classed as Beginner in Engineering Mechanics (topic 23 of 106). It is an entry-level topic. It relies only on basic school mathematics and the ideas introduced earlier in this discipline.
Want to practise? Open the interactive course for quick checks, quizzes, simulations and progress tracking.