Biomechanics Lecture – Acceleration & Momentum

Acceleration

• Definition: rate of change of velocity over time \left(A = \frac{V2 - V1}{T}\right).
• Types:
  • Positive (speeding up)
  • Negative / deceleration (slowing down)
  • Zero (constant velocity).
• Performance links:
  • Directly tied to power production.
  • Key for explosive starts (e.g., 100 m sprint) and rapid direction changes (agility).
  • Faster acceleration → opponents have less reaction time & athlete reaches top speed sooner.

Momentum

• Definition: product of mass and velocity \left(M = m \times V\right).
• Impact in sport:
  • Greater momentum → harder to stop in collisions.
  • Heavy, fast athletes (e.g., rugby forwards) are difficult to tackle.
  • Lighter athletes reach peak momentum faster because they require less force to accelerate.
  • Tackling lighter defenders requires technique adjustments against heavier opponents.

Key Takeaways

• Train acceleration to boost power, speed off the mark, and agility.
• Momentum management (gaining or halting) is crucial in contact sports; mass and velocity must be balanced in strategy and technique.