IB DP Physics: HL復習筆記2.1.7 Projectile Motion
Projectile Motion
- The trajectory of an object undergoing projectile motion consists of a?vertical?component and a?horizontal?component
- These need to be evaluated separately
- Some key terms to know, and how to calculate them, are:
- Time of flight:?how long the projectile is in the air
- Maximum height attained:?the height at which the projectile is momentarily at rest
- Range: the horizontal distance traveled by the projectile
How to find the time of flight, maximum height and range
Problems involving projectile motion
- There are two main considerations for solving problems involving two-dimensional motion of a projectile
- Constant velocity in the horizontal direction
- Constant acceleration in a perpendicular direction
- The only force acting on the projectile, after it has been released, is?gravity
- There are three possible scenarios for projectile motion:
- Vertical?projection
- Horizontal?projection
- Projection?at an?angle
Worked Example
To calculate vertical projection (free fall)
A science museum designed an experiment to show the fall of a feather in a vertical glass vacuum tube.
The time of fall from rest is 0.5 s.
What is the length of the tube, L?
Worked Example
To calculate horizontal projection
A motorcycle stunt-rider moving horizontally takes off from a point 1.25 m above the ground, landing 10 m away as shown.
What was the speed at take-off? (ignoring air resistance)
Worked Example
To calculate projection at an angle
A ball is thrown from a point P with an initial velocity u of 12 m s-1?at 50° to the horizontal.
What is the value of the maximum height at Q? (ignoring air resistance)
Exam Tip
Make sure you don’t make these common mistakes:
- Forgetting that deceleration is negative as the object rises
- Confusing the direction of sin θ and cos θ
- Not converting units (mm, cm, km etc.) to metres
Further, it is worth noting that projectile motion is typically symmetrical when air resistance is ignored allowing for use of the peak to find the time of total flight or total horizontal distance by doubling the amount to get from the start point to the peak.
以上就是關于【IB DP Physics: HL復習筆記2.1.7 Projectile Motion】的解答，如需了解學校/賽事/課程動態，可至翰林教育官網獲取更多信息。
往期文章閱讀推薦：
翰林獨家 | 經濟學競賽核心精講，一冊打通NEC/IEO/USAEBO！
2026 AMC10/12美國數學競賽新賽季！【翰林教育 × 清華大學出版社】獨家教材全面發售！
翰林AMC8視頻課重磅上線！
國際競賽真題資源免費領取
