P5: Newton 's Laws of Motion Physics GCSE

• What does Newton's First Law of Motion state?

  Objects remain at rest or constant velocity unless acted on
• What happens if the resultant force on an object is zero?

  The object remains stationary or moves uniformly
• What does it mean for an object to move with constant velocity?

  It moves at the same speed and direction
• How can Newton's First Law explain uniform motion?

  Balanced forces result in zero resultant force
• What is required for constant velocity to be achieved?

  Forces on the object must be balanced
• Why is velocity considered a vector quantity?

  It has both magnitude and direction
• What does Newton's Second Law of Motion state?

  Acceleration is proportional to resultant force and inversely proportional to mass
• How does resultant force affect acceleration?

  A larger force results in larger acceleration
• What happens to acceleration if mass increases with constant force?

  Acceleration decreases as mass increases
• What is the equation for Newton's Second Law?

  F = ma
• If a car has a mass of 900 kg and accelerates at $9 \text{ m/s}^2$, what is the force?


  $8100 \text{ N}$
• How does mass affect acceleration when the same force is applied?

  Greater mass results in smaller acceleration
• How do you calculate acceleration from change in velocity?

  Acceleration = change in velocity / time
• What is the estimated acceleration of a car that stops from $20 \text{ m/s}$ in $0.1 \text{ s}$?


  $-200 \text{ m/s}^2$
• What is the estimated force on a passenger with mass $70 \text{ kg}$ during deceleration?


  $-14000 \text{ N}$
• What are the key variables in investigating force and acceleration?

  • Independent variable: Force (F)
  • Dependent variable: Acceleration (a)
  • Control variables: Mass (m)
• What is the aim of the experiment investigating the effect of mass on acceleration?

  • Investigate how varying mass affects acceleration
  • Keep force constant during the experiment
• What is the method for measuring acceleration in the experiments?

  1. Measure intervals on the bench
  2. Use a pulley system with a toy car
  3. Record times for each interval
  4. Calculate average speed and acceleration
• What should be done with the results from the experiments?

  • Determine average speed between intervals
  • Compare acceleration for different weights
  • Analyze how acceleration varies with mass
• What is the aim of the experiment investigating mass on acceleration?

  To investigate the effect of varying mass
• What is the independent variable in the experiment?

  Mass, m
• What is the dependent variable in the experiment?

  Acceleration, a
• What are the control variables in the experiment?

  • Force, F
• How should the intervals be measured on the bench?

  Every 0.2 m for a total distance of 1 m
• What should be done with the string in the experiment?

  It must be horizontal and parallel to the bench
• What is the first step after attaching the bench pulley?

  Put a 200 g mass on the car
• What should be done to ensure the car accelerates gently?

  Select a weight that provides constant force
• What should you do when releasing the car?

  Release it simultaneously with starting the stopwatch
• Why is it important to record results in a table?

  To calculate an average time for each interval
• What should be done for increasing mass on the car?

  Repeat steps 6−9 for 400 g, 600 g, 800 g, and 1000 g
• What is the process to analyze results in the experiment?

  1. Determine average speed between intervals
  2. Use distance and average time to calculate speed
  3. Compare average speed for different weights
  4. Calculate acceleration using the equation
• What is a systematic error in the experiment?

  Not transferring weights to maintain constant mass
• What is a random error in the experiment?

  Measurement errors in timing intervals
• How should the toy car be started?

  By releasing it without a push
• What safety consideration should be taken?

  Don't stand beneath the weight hanger
• What is the sequence to write about experiments?

  1. State the equation used
  2. List the apparatus needed
  3. State measurements and how to measure them
  4. Mention repeating measurements and taking averages
• What does Newton's third law state?

  Forces between two bodies are equal and opposite
• What do force pairs in Newton's third law represent?

  Equal and opposite forces acting on different objects
• How does Newton's third law explain walking?

  Foot pushes ground back, ground pushes foot forward
• Why is William correct regarding the free-body force diagram?

  It shows forces acting on one object only