Forces

• What is the formula for calculating speed?

  Speed = distance/time
• What type of quantity is speed?

  Speed is a scalar quantity.
• Which of the following is a scalar quantity?

  Speed
• What is a vector quantity?

  A vector quantity has both a magnitude and a direction.
• Which of the following is a vector quantity?

  Velocity
• How do speed and velocity differ?

  Speed measures how quickly something is moving, while velocity includes direction.
• What is the difference between distance and displacement?

  Distance is how far an object has travelled, while displacement shows how far an object is from its starting point.
• What can a distance-time graph be used for?

  A distance-time graph can be used for calculating the speed of a moving object.
• What does a steeper line on a distance-time graph indicate?

  A steeper line indicates a greater speed.
• What does a non-straight line on a distance-time graph represent?

  A non-straight line represents a speed that is changing.
• What is acceleration?

  Acceleration is the rate at which the speed of a moving object is changing.
• What type of quantity is acceleration?

  Acceleration is a vector quantity.
• What does a negative value for acceleration indicate?

  A negative value for acceleration means the object is slowing down.
• What can a speed-time graph be used for?

  A speed-time graph can be used for calculating the acceleration of a moving object.
• What does a negative gradient on a speed-time graph indicate?

  A negative gradient indicates deceleration.
• What does a level line on a speed-time graph represent?

  A level line represents constant speed.
• What does a level line following the horizontal axis mean on a speed-time graph?

  A level line following the horizontal axis means the object is not moving.
• How can a speed-time graph be used to calculate distance travelled?

  By calculating the area under the graph.
• What is a force?

  A force is a push or pull.
• What effect do forces have on objects?

  Forces cause objects to change speed and can squash or stretch them.
• How can forces work through objects?

  Forces can work through contact or at a distance.
• What is the unit for force?

  The unit for force is the newton.
• What type of quantities are all forces?

  All forces are vector quantities.
• What is weight?

  Weight is the effect of gravity on a mass, acting straight down.
• What is reaction force?

  Reaction is the effect of a surface pushing on an object, at right angles to the surface.
• What is upthrust or lift?

  Upthrust or lift is the supporting force exerted by a fluid on an object, acting upwards.
• What is friction or air resistance?

  Friction or air resistance is a resistive force attempting to slow an object, by opposing the motion.
• What is thrust or driving force?

  Thrust or driving force is the pull of a machine doing work to move an object, in the direction of motion.
• What is tension?

  Tension is the pull of a rope, chain, or wire, acting along the rope away from the object.
• What do balanced forces tell us about an object’s motion?

  Balanced forces mean the object moves at a constant speed.
• What is the resultant force?

  The resultant force is a measure of how unbalanced the forces are, with a direction stated.
• What happens if the forces acting on an object are balanced?

  If the forces are balanced, the resultant force is zero, and the object moves at a constant speed.
• What happens if the forces acting on an object are unbalanced?

  If the forces are unbalanced, the object’s speed will change and it will accelerate in the direction of the resultant force.
• What does a resultant force acting backwards do to an object?

  A resultant force acting backwards decelerates the object.
• What is mass?

  Mass is a measure of how much matter makes up an object.
• What is weight measured in?

  Weight is measured in newtons.
• How does mass differ from weight?

  The mass of an object does not change in different parts of the universe, but the weight does.
• What is the relationship between gravitational field strength and weight?

  The greater the gravitational field strength, the greater the weight.
• What happens to an object at rest when acted on by an external unbalanced force?

  An object will remain at rest unless acted on by an external unbalanced force.
• What happens to an object in motion when acted on by an external unbalanced force?

  An object will remain in motion unless acted on by an external unbalanced force.