Projectile and Circular Motion – HSC Physics Advanced Mechanics
Summary:
The text covers Projectile and Circular Motion topics, including analysing motion, deriving relationships between variables, and analysing forces. It also discusses gravitational forces related to Newton’s Law of Universal Gravitation, Kepler’s Laws of Planetary Motion, and concepts such as escape velocity and gravitational potential energy. The text provides qualitative and quantitative explanations and examples of how these topics apply to specific situations.
Excerpt:
Projectile and Circular Motion
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Inquiry question: how can models that are used to explain projectile motion be used to analyse and make predictions? |
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● analyse the motion of projectiles by resolving the motion into horizontal and vertical components, making the following assumptions:
– a constant vertical acceleration due to gravity – zero air resistance |
| Textbook Reference: |
Components of Projectile Motion
- The only force acting on something moving and falling is gravity g = 8ms-2
- The projectile is determined by its initial velocity → uy = uSinθ ux = uCosθ
- Assume there is no air resistance
- There is no acceleration in the horizontal direction; gravity only acts vertically
- The curvature of the earth is ignored
- Vertical velocity has a positive initial and then is at a constant decline
- Acceleration is constant -9.8ms-2
- The total energy is constant
- After launch, gravity takes over and is the only force that acts on the projectile.
| Horizontal direction (x) | Vertical Direction (y) |
| 𝑣 = 𝑢
𝑥 𝑥 |
2 2
𝑣 = 𝑢 + 2𝑎 𝑠 𝑦 𝑦 𝑦 𝑦 |
| 𝑠 = 𝑢 𝑡
𝑥 𝑥 |
𝑠 = 𝑢 𝑡 + 1 𝑎 2
𝑦 𝑦 2 𝑡 𝑦 |
| 𝑣 = 𝑢 + 𝑎 𝑡
𝑦 𝑦 𝑦 |
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Inquiry question: how can models that are used to explain projectile motion be used to analyse and make predictions? |
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● apply the modelling of projectile motion to derive the relationships between the following variables quantitatively:
– initial velocity – launch angle – maximum height – time of flight – final velocity – launch height – horizontal range of the projectile |
| Textbook Reference: |
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