Time Intervals

Understanding Time Intervals

  • Time intervals are the time that elapses in between two events.
  • They are typically expressed in units of time such as seconds, minutes, hours, days, and so forth.
  • Important for solving problems involving time, speed, and distance.

Converting Time Intervals

  • Be familiar with conversions among different units of time.
    • 60 seconds equals 1 minute.
    • 60 minutes equals 1 hour.
    • 24 hours equals 1 day.
  • We often need to standardise time intervals to the same units before solving problems or comparisons.
  • Remember to convert larger units of time into smaller ones where possible, and vice versa, to make the operation easier.

Calculating Time Intervals

  • Can involve addition, subtraction, multiplication, or division, depending on the problem’s requirement.
  • To find the time interval between two specific points in time, subtract the smaller time from the larger. For example, to find the interval from 3:15 pm to 5:45 pm, subtract the former from the latter.
  • For elapsed time, simply add up the given time intervals.

Application in Problems of Speed, Distance, and Time

  • Sometimes, the speed and distance travelled are given, and we need to calculate the time taken. In this case, use the formula: Time = Distance ÷ Speed.
  • If the speed varies during a journey, divide the journey into separate segments and calculate the time for each. Then, add these times to get the full journey time.
  • All time interval related calculations require a clear understanding of the relationship between speed, distance and time.

Sample Problems for Practice

After grasping these concepts, attempt a few practice problems based on time intervals. This will test your understanding and aptitude for calculating and manipulating time intervals effectively.

  • Worked examples will help you understand the step-by-step problem-solving approach.
  • Feedback on attempted problems is helpful for identifying mistakes and learning from them. Practice papers may also help with this.

Review

Regularly review your learning to ensure these rules and methods for dealing with time intervals are understood and remembered. Active recall and practice are the most effective revision strategies.