C4 - Angular Motion, Projectile Motion + Fluid Mechanics Flashcards
What is projectile motion?
The movement of an object through the air, influenced only by gravity and air resistance.
Example: A javelin in flight.
What are parabolic and non-parabolic flight paths?
- Parabolic: Symmetrical flight due to small air resistance, weight is domiant force (e.g., shot put).
- Non-parabolic: Asymmetrical due to air resistance being domiant force, small weight (e.g., shuttlecock).
What are the 4 factors affecting projectile motion?
- Speed of release: Higher speed = greater distance.
- Angle of release: 45° is optimal for max horizontal distance.
- Height of release: Higher release = longer flight time.
- Aerodynamic factors: Drag and lift influence trajectory.
How does Newton’s First Law apply to angular motion?
A rotating object stays in motion unless acted upon by an external torque.
Example: A gymnast spinning in the air continues spinning unless they apply force to stop.
How does Newton’s Second Law apply to angular motion?
Angular acceleration is proportional to the torque applied and inversely proportional to moment of inertia.
Example: A figure skater spins faster when tucking their arms in.
How does Newton’s Third Law apply to angular motion?
For every angular action, there is an equal and opposite reaction.
Example: A diver tucks in mid-air to increase spin, then extends arms before landing.
What is axis of rotation?
The imaginary line about which a body rotates.
Example: A gymnast somersaulting rotates around the transverse axis.
What is angular displacement?
The change in angle between the start and end position of rotation.
What is angular velocity?
The rate of change of angular displacement over time.
Formula: Angular velocity = angular displacement ÷ time
What is moment of inertia?
A body’s resistance to rotation, determined by mass and distribution of mass from axis of rotation.
How does moment of inertia relate to angular velocity?
Lower moment of inertia = higher angular velocity.
Example: A tucked somersault spins faster than a layout.
What is angular momentum?
The amount of rotational motion a body has, calculated by: Angular Momentum = Moment of Inertia × Angular Velocity.
How is angular momentum conserved?
If no external torque is applied, angular momentum remains constant.
Example: A skater pulls in arms to spin faster but total momentum stays the same.
How does fluid friction affect projectiles?
Air resistance (drag) slows objects down and changes their path.
How can drag be reduced in sports?
- Reducing front cross-sectional area (e.g., sprinters adopting a low, narrow stance).
- Streamlining body position (e.g., cyclists wearing skinsuits).
- Surface characteristics (e.g., golf ball dimples reduce drag).
What is Bernoulli’s Principle?
Faster-moving air creates low pressure, while slower-moving air creates high pressure, resulting in lift force.
How does Bernoulli’s Principle apply to sport?
- Upward lift: E.g., a discus thrown at the correct angle.
- Downward lift (negative lift): E.g., F1 cars use inverted wings to increase traction.
What is angle of attack?
The angle between an object’s motion and airflow, affecting lift and drag.
What is the Magnus Effect?
A spinning object creates pressure differences, making it curve in flight.
What is topspin?
- Faster air over the top, lower pressure.
- Slower air below, higher pressure.
- Ball dips quickly.
Example: tennis forehand.
What is backspin?
- Slower air over the top, higher pressure.
- Faster air below, lower pressure.
- Ball stays in the air longer.
Example: a lofted golf shot.
What is sidespin?
Causes sideways curve.
Example: bending a football free kick.
What is laminar flow?
Smooth airflow, reducing drag.
Example: aerodynamic cycling helmets.
What is turbulent flow?
Chaotic airflow, increasing drag.
Example: poor body positioning in sprinting.
