(455) Impulse [IB Physics SL/HL]

Impulse Overview

  • Impulse is defined as the change in momentum.

  • Formula for impulse:

    • Impulse = F × ΔT = ΔP (where F is force, ΔT is change in time, and ΔP is change in momentum).

Understanding Impulse

  • Impulse can be visualized as a force applied over a short duration (e.g., kicking a ball).

  • The relationship between impulse and the graph of force (F) versus time (ΔT):

    • The area under the F vs. ΔT graph represents impulse.

Analyzing Graphs

  • When analyzing a graph, there are three main approaches:

    1. Read a value directly:

      • Find a value on the x or y-axis and relate it to the other.

    2. Use the gradient:

      • Calculate the slope (rise over run), with units being Δy/Δx (e.g., Newtons/second).

    3. Calculate the area under the curve:

      • Area = length × width, with units being y * x (e.g., Newtons × seconds = Impulse in Newton seconds).

Key Takeaways

  • Impulse (F × ΔT) is the area under the F vs. ΔT curve.

  • Units of impulse can be Newton seconds or kilogram meters per second.

  • Understanding how to extract values from a graph is crucial for solving related questions.