Forces & Motion

• What type of quantity is distance: scalar or vector?

  Distance is a scalar quantity.
• Why does a distance quantity not require a specific direction?

  Because it is defined only by magnitude, making it a scalar quantity.
• If an object moves 3 metres to the left and then 3 metres back to its initial position, what is the total displacement?

  The total displacement is zero.
• Why is the displacement of the object zero in the given scenario?

  Because the object starts and ends at the same point.
• What is a typical value for the speed of sound?

  330 m/s
• What is a typical value for human walking speed?

  1. 5 m/s
• What is a typical value for human running speed?

  3 m/s
• What is a typical value for human cycling speed?

  6 m/s
• What is the equation linking distance, speed, and time?

  Distance = Speed x Time
• What are the appropriate units for distance, speed, and time in the equation linking them?

  Distance (m), Speed (m/s), Time (s)
• Why can an object travelling at a constant speed in a circle not have a constant velocity?

  Because the direction is continuously changing, affecting the velocity.
• How can speed be calculated from a distance-time graph?

  The speed is equal to the gradient of the graph.
• What must be done to calculate speed at a given time from a distance-time graph for an accelerating object?

  You must draw a tangent to the curve at the required time and calculate the gradient of the tangent.
• What is the equation for the average acceleration of an object?

  Acceleration = (Change in Velocity)/(Time Taken)
• What are the appropriate units for acceleration, velocity, and time in the acceleration equation?

  Acceleration (m/s²), Velocity (m/s), Time (s)
• How can the distance travelled by an object be calculated from a velocity-time graph?

  It is equal to the area under the graph.
• What is the approximate value for the acceleration of an object in free fall under gravity near the Earth’s surface?

  1. 8 m/s²
• What can be said about the resultant force acting on an object when it is falling at terminal velocity?

  The resultant force is zero.
• What happens to an object at terminal velocity?

  The object is moving at a constant speed and isn’t accelerating.
• What is Newton’s first law for a stationary object?

  If the resultant force on a stationary object is zero, the object will remain at rest.
• What is Newton’s first law for a moving object?

  If the resultant force on a moving object is zero, the object will remain at constant velocity (same speed in same direction).
• What can be said about the braking forces and driving forces when a car is travelling at constant velocity?

  The braking forces are equal to the driving forces.
• If an object changes direction but remains at a constant speed, is there a resultant force?

  Yes, there is a resultant force due to the change in direction.
• What are the key concepts of scalar and vector quantities?

  • Scalar quantities have magnitude only (e.g., distance, speed).
  • Vector quantities have both magnitude and direction (e.g., displacement, velocity).
• What are the key points regarding Newton's first law of motion?

  • A stationary object remains at rest if the resultant force is zero.
  • A moving object continues at constant velocity if the resultant force is zero.
• What does Newton's first law state for a moving object?

  If the resultant force on a moving object is zero, the object will remain at constant velocity.
• Is there a resultant force if an object changes direction but remains at a constant speed?

  Yes, there is a resultant force because there is a change in velocity.
• What is inertia?

  Inertia is the tendency of an object to continue in its state of rest or uniform motion.