CONVERSIONS: MILES PER HOUR (MPH) / KILOMETERS PER HOUR (KPH) / KNOTS

KEY CONCEPTS

  1. Speeds are rates of motion and are measured in terms of a unit of distance covered in a unit of time (usually one hour).
  2. Wind speed is expressed in terms of miles per hour, kilometers per hour, a force on the Beaufort Scale of Wind Velocity, or knots. A knot is one nautical mile per hour.
  3. The ability to convert wind speed from one unit of measurement to another is an important meteorological skill.
 

MATERIALS

  • mathematical worksheet (optional)
  • examples of use of various units: miles per hour, kilometers per hour, and knots.
  • student journals
 
 

PROCEDURE

  
 
 

Activity

  1. Display the following conversion formulas for student reference:
    WHEN YOU KNOW: MULTIPLY BY: TO FIND:
    KILOMETER (KM) 0.6 MILE (MI)
    MILE (MI) 1.6 KILOMETER (KM)
    KNOT (KT) 1.15 MILE (MI)
    KNOT (KT) 1.85 KILOMETER (KM)
  2. As a group, calculate several conversions from one unit of measurement to another.
  3. Enter the conversion formulas in the student journals and challenge students to convert various sample speeds from one unit of measurement to another.
 
 

Assessment Ideas

  • accuracy of student conversions
  
 
 

CROSS-CURRICULAR IDEAS

  • Physics: How can wind be measured as a force?
  • History/ Social studies: Wind has always caused people trouble. Find some examples of wind problems and how people have solved the problem.
 
 

VOCABULARY

  • speed: the rate of motion, as measured in terms of a unit of distance covered in a unit of time knot ­ a unit measuring speed, or one nautical mile per hour.
 
 

SOURCE

  • "Winds of Change" educational CD-ROM, Copyright Caltech and NASA/Jet Propulsion Laboratory