Content:
PH12-12
How can models that are used to explain projectile motion be used to analyse and make predictions?
- 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
- Apply the modelling of projectile motion to quantitatively derive the relationships between the following variables:
- initial velocity
- launch angle
- maximum height
- time of flight
- final velocity
- launch height
- horizontal range of the projectile
- Conduct a practical investigation to collect primary data in order to validate the relationships derived above.
- Solve problems, create models and make quantitative predictions by applying the equations of motion relationships for uniformly accelerated and constant rectilinear motion
Why do objects move in circles?
- Conduct investigations to explain and evaluate, for objects executing uniform circular motion, the relationships that exist between:
- centripetal force
- mass
- speed
- radius
- Analyse the forces acting on an object executing uniform circular motion in a variety of situations, for example:
- cars moving around horizontal circular bends
- a mass on a string
- objects on banked tracks
- Solve problems, model and make quantitative predictions about objects executing uniform circular motion in a variety of situations, using the following relationships:
- \( a_c=\frac{v^2}{r} \)
- \( v=\frac{2 \pi r}{T} \)
- \(F_c=\frac{mv^2}{r} \)
- \( \omega=\frac{ \bigtriangleup \theta}{t} \)
How does the force of gravity determine the motion of planets and satellites?
- Apply qualitatively and quantitatively Newton's Law of Universal Gravitation to:
- determine the force of gravity between two objects \( F=\frac{GMm}{r^2} \)
- investigate the factors that affect the gravitational field strength \( g=\frac{GM}{r^2} \)
- predict the gravitational field strength at any point in a gravitational field, including at the surface of a planet
- Investigate the orbital motion of planets and artificial satellites when applying the relationships between the following quantities:
- gravitational force
- centripetal force
- centripetal acceleration
- mass
- orbital radius
- orbital velocity
- orbital period
- Predict quantitatively the orbital properties of planets and satellites in a variety of situations, including near the Earth and geostationary orbits, and relate these to their uses
- Investigate the relationship of Kepler’s Laws of Planetary Motion to the forces acting on, and the total energy of, planets in circular and non-circular orbits using:
- \( v=\frac{2 \pi r}{T} \)
- \( \frac{r^3}{T^2}=\frac{GM}{4 \pi_2} \)
- Derive quantitatively and apply the concepts of gravitational force and gravitational potential energy in radial gravitational fields to a variety of situations, including but not limited to:
- the concept of escape velocity \( v_{esc}=\sqrt{\frac{2GM}{r}} \)
- total potential energy of a planet or satellite in its orbit \( U=-\frac{GMm}{r} \)
- total energy of a planet or satellite in its orbit \( U+K=-\frac{GMm}{2r} \)
- energy changes that occur when satellites move between orbits
- Kepler’s Laws of Planetary Motion