Describing Motion

• What is distance a measure of?

  Distance is a measure of how far an object travels.
• What type of quantity is distance?

  Distance is a scalar quantity.
• How far did the athletes run in the example provided?

  The athletes ran a total distance of 300 m.
• What does displacement measure?

  Displacement measures how far something is from its starting position, along with its direction.
• What type of quantity is displacement?

  Displacement is a vector quantity.

  
• If the athletes ran a total distance of 300 m but ended up 100 m from where they started, what is their displacement?

  Their displacement is 100 m to the right.
• What would the final displacement be if the athletes had run a full 400 m?

  The final displacement would be zero.
• What is speed a measure of?

  Speed is the distance an object travels every second.
• What type of quantity is speed?

  Speed is a scalar quantity.
• How is average speed calculated?

  Average speed is calculated using the equation: speed = distance / time.

  
• What are the units for speed?

  Speed is measured in metres per second (m/s).
• What is an example of average speed for a hiker?

  An average speed of a hiker might be 2.0 m/s.
• What is an example of average speed for a bumblebee?

  A particularly excited bumblebee can have average speeds of up to 4.5 m/s.
• What does average speed represent?

  Average speed represents the mean speed of a moving object.

  
• Why is it important to consider total distance and time when calculating average speed?

  Because the speed of an object can change at different moments.

  
• What does non-uniform motion refer to?

  Non-uniform motion refers to motion that is changing.
• What can changing motion involve?

  Changing motion can involve changing speed, direction, or both.
• What is a typical speed for a person walking?

  A typical speed for a person walking is about 1.5 m/s.
• What factors can affect the typical speeds of a person walking?

  Factors include age, terrain, fitness, and distance.
• What is a typical value for the speed of sound in air?

  A typical value for the speed of sound in air is 330 m/s.
• What is a typical value for the speed of sound in seawater?

  A typical value for the speed of sound in seawater is around 1500 m/s.
• How can speed be measured?

  Speed can be measured by timing how long it takes to travel a known distance.

  
• What equipment can be used to measure distance and time accurately?

  Equipment includes a metre rule, timer, tape measure, or trundle wheel.
• What is a more appropriate tool for measuring long distances?

  A trundle wheel is ideal for measuring long distances.
• How do light gates measure time accurately?

  Light gates start a timer when an object passes through and stop it when the object passes a second gate.
• What does a single light gate measure?

  A single light gate measures the speed of an object as it passes through.

  
• What is the equation for calculating speed for objects moving at constant speed?

  The equation is \( v = \frac{s}{t} \), where \( v \) is speed, \( s \) is distance, and \( t \) is time.

  
• How do you calculate the distance travelled by a plane flying at 250 m/s for 2 hours?

  Convert 2 hours to seconds and use \( s = v \times t \) to find \( s = 250 \times 7200 = 1,800,000 \text{ m} \).
• What is average speed in non-uniform motion?

  Average speed is calculated using the total distance divided by the time taken.

  
• How do you calculate Florence Griffith Joyner's average speed during her 100 m world record race?

  Average speed = \( \frac{100 \text{ m}}{10.49 \text{ s}} \approx 9.53 \text{ m/s} \).
• What is the difference between speed and velocity?

  Velocity includes both magnitude and direction, while speed only includes magnitude.
• Why is velocity considered a vector quantity?

  Because it describes both magnitude and direction.

  
• How does circular motion affect velocity?

  In circular motion, the speed may be constant, but the direction is always changing, thus changing the velocity.
• What is the speed of the International Space Station as it orbits the Earth?

  The International Space Station travels at a constant speed of about 7660 m/s.

  
• Why does motion in a circle involve constant speed but changing velocity?

  Because velocity is a vector quantity, so both magnitude and direction are important.
• What does a distance-time graph show?

  A distance-time graph shows how the distance of an object varies over time.

  
• What does a straight line on a distance-time graph represent?

  A straight line represents constant speed.

  
• What does the slope of a straight line on a distance-time graph indicate?

  The slope indicates the magnitude of the speed.

  
• What does a very steep slope on a distance-time graph mean?

  A very steep slope means the object is moving at a large speed.

  
• What does a shallow slope on a distance-time graph indicate?

  A shallow slope means the object is moving at a small speed.