5.4.4 Calculating Speed

• What is the basic formula for speed?

  Speed = Distance / Time
• How is speed measured?

  Speed is measured in meters per second (m/s) or kilometers per hour (km/h).
• What is the unit of measurement for distance?

  Distance is measured in meters (m) or kilometers (km).
• How is time measured in speed calculations?

  Time is measured in seconds (s) or hours (h).
• What unit is used for scientific calculations of speed?

  Meters per second (m/s) is used for scientific calculations.
• In what context is kilometers per hour (km/h) typically used?

  Kilometers per hour (km/h) is used for everyday contexts, such as road speeds.
• How do you convert speed from meters per second to kilometers per hour?

  To convert from m/s to km/h, multiply by 3.6.
• How do you convert speed from kilometers per hour to meters per second?

  To convert from km/h to m/s, divide by 3.6.
• What are the steps to calculate speed?

  1. Measure Distance: Use a ruler or measuring tape.

  2. Measure Time: Use a stopwatch to time the travel.

  3. Apply the Formula: Substitute distance and time into Speed = Distance / Time.
• If a car travels 150 meters in 15 seconds, what is its speed?

  The speed is 10 m/s.
• How do you convert a speed of 8 m/s to kilometers per hour?

  The speed in km/h is 28.8 km/h.
• What is the speed of a runner who covers 400 meters in 50 seconds?

  The speed is 8 m/s.
• How do you calculate average speed when traveling different distances at different speeds?

  1. Calculate Total Distance: Sum all distances traveled.

  2. Calculate Total Time: Sum all time taken for each segment.

  3. Use the formula: Average Speed = Total Distance / Total Time.
• If a person walks 5 kilometers at 4 km/h and then 3 kilometers at 6 km/h, what is the total distance traveled?

  The total distance is 8 kilometers.
• How long does it take to walk 5 kilometers at a speed of 4 km/h?

  It takes 1.25 hours.
• How long does it take to walk 3 kilometers at a speed of 6 km/h?

  It takes 0.5 hours.
• What is the total time taken for a journey of 5 km at 4 km/h and 3 km at 6 km/h?

  The total time is 1.75 hours.
• What is the average speed for a journey of 8 kilometers completed in 1.75 hours?

  The average speed is approximately 4.57 km/h.
• What practical considerations should be taken into account when measuring speed?

  • Ensure precise measurement of distance and time.
  • Maintain consistency in units or convert them appropriately.
  • Use a precise stopwatch, especially for short intervals.
• What is the summary of speed calculation?

  • Use Speed = Distance / Time.
  • Convert between m/s and km/h as needed.
  • Calculate average speed using total distance and total time.