Section 1 - Motion, Forces and Conservation of energy

• What are scalar quantities?

  Quantities with magnitude only
• Name three examples of scalar quantities.

  Speed, distance, mass
• What are vector quantities?

  Quantities with magnitude and direction
• Name three examples of vector quantities.

  Force, velocity, displacement
• What is the difference between distance and displacement?

  Distance is scalar; displacement is vector
• How is speed defined?

  How fast an object is moving
• What is the formula for calculating average speed?

  Distance travelled = average speed × time
• What is the typical speed of a walking person?

  1.4 m/s
• What is the typical speed of a running person?

  3 m/s
• What is the typical speed of a cyclist?

  5.5 m/s
• How is velocity defined?

  Speed in a specific direction
• What does acceleration measure?

  Change in velocity over time
• What is the formula for acceleration?

  Acceleration = (v - u) / time
• What is the approximate acceleration due to gravity near Earth's surface?

  10 m/s²
• What does a distance/time graph show?

  Distance against time for an object
• What does the gradient of a distance/time graph represent?

  Speed of the object
• What does a velocity/time graph show?

  Velocity against time for an object
• What does the gradient of a velocity/time graph represent?

  Acceleration of the object
• What does the area under a velocity/time graph represent?

  Distance travelled in that time
• What does Newton's First Law state about a stationary object?

  It doesn't move if no resultant force acts
• What happens to a moving object if no resultant force acts on it?

  It continues moving at the same velocity
• What does a non-zero resultant force cause an object to do?

  It accelerates in the direction of the force
• What is Newton's Second Law formula?

  F = ma
• How is acceleration related to resultant force?

  Acceleration is directly proportional to resultant force
• How is acceleration related to mass?

  Acceleration is inversely proportional to mass
• What does Newton's Third Law state about interacting objects?

  They exert equal and opposite forces on each other
• What happens when a rocket exhausts gas downwards?

  It causes an equal and opposite force upwards
• What is weight defined as?

  Force acting on an object due to gravity
• What is the formula for weight?

  W = mg
• How does weight vary with location?

  Depends on gravitational field strength
• What is inertial mass?

  Measure of how hard it is to change velocity
• What is the formula for calculating momentum?

  p = mv
• How does mass affect momentum?

  Greater mass means greater momentum
• How does velocity affect momentum?

  Greater velocity means greater momentum
• What is the principle of conservation of momentum?

  Total momentum before equals total after
• What happens to momentum in a closed system?

  It remains constant before and after events
• What is a typical human reaction time?

  0.2 - 0.9 seconds
• What are three factors affecting reaction times?

  Tiredness, drugs, distractions
• What is the stopping distance equation?

  Stopping distance = thinking + braking distance
• What increases thinking distance?

  Faster speed, longer reaction times