Physics Paper 2

Overview of Physics Concepts for AQA Exam

• Importance of familiarity with equations and units for exam success.

• Availability of a comprehensive revision guide.

Scalar and Vector Quantities

• Scalar Quantity: A number only. Examples include:

  • Distance

  • Mass

  • Speed

• Vector Quantity: A number and a direction. Examples include:

  • Displacement (distance in direction)

  • Weight (mass influenced by gravity)

  • Velocity (speed in a direction)

  • Acceleration

  • Force

  • Momentum

Forces and Resultant Force

• To find the resultant force:

  • Example Calculation: 10N + 10N - 5N = 5N in a specified direction.

  • Zero resultant force implies no movement, e.g., 2N - 2N = 0N.

Weight and Mass

• Weight: W = Mass (kg) × Gravity (N/kg)

  • Measured in newtons.

• Mass: Constant regardless of location; measured in kilograms.

• Example: Reduced weight on the moon due to lower gravitational force.

Work Done

• Work Formula: Work (J) = Force (N) × Distance (m)

  • 1 Joule = 1 Newton-meter.

  • Force causes an object to deform (squash/stretch).

Hooke's Law

• Experiment with springs:

  • Direct relationship until the limit of proportionality.

• Force: F = Spring Constant (N/m) × Extension (m)

Energy Principles

• Kinetic Energy Formula: KE = 1/2 × Mass (kg) × Velocity² (m/s²)

  • Kinetic energy measured in joules.

Properties of Fluids

• Fluids include liquids (incompressible) and gases (compressible).

• Pressure Formula: Pressure (Pa) = Force (N) / Area (m²)

  • Units can vary (e.g., N/m² or N/cm²).

• Pressure depth relation: P = Height (m) × Density (kg/m³) × Gravity (N/kg).

Motion and Graphs

• Distance Formula: Distance (m) = Speed (m/s) × Time (s)

• Distance-Time Graphs:

  • Increasing slope = moving; flat line = stationary.

• Velocity-Time Graphs:

  • Flat line = constant speed; increasing slope = acceleration.

  • Area under graph represents distance traveled:

    • Triangle Area = 1/2 × Base × Height

    • Rectangle Area = Base × Height

Acceleration

• Acceleration Formula: Acceleration (m/s²) = Change in Velocity (m/s) / Time (s)

  • Change in velocity calculated through:

    • Final Velocity - Initial Velocity

• Kinematic Equation: Final Velocity² - Initial Velocity² = 2 × Acceleration × Distance

Terminal Velocity

• Occurs when forces are balanced during free fall.

• Speed of freely falling objects at terminal velocity is approximately 9.8 m/s.

Newton's Cradle

• Demonstrates physics principles:

  • Inertia: Objects remain in state of rest/motion unless acted upon.

  • Conservation of Energy: Energy transformed (e.g., into sound and heat).

  • Newton's Third Law: For every action, there is an equal and opposite reaction.

Force Calculation

• Force Formula: Force (N) = Mass (kg) × Acceleration (m/s²)

Car Stopping Distance

• Comprised of:

  • Thinking Distance: Affected by reaction time influenced by factors such as:

    • Alcohol and drugs (negative impact)

    • Caffeine (positive impact)

    • Tiredness (negative impact)

  • Braking Distance: Influenced by tire conditions and road conditions (e.g., snow, ice).