Let us try to understand the concept of elapsed time
Tommy starts his day at 6.00 am.
He goes to school at 7.00 am and comes back home at 12.00 pm.
He then goes for his piano lessons at 3.00 pm and to the park with his mother at 5.00 pm.
Tommy has his dinner at 7.00 pm and goes to bed at 8.00 pm.
Now, what if we want to calculate the total time for which Tommy was awake? To do this, we will need to calculate the total time between 6.00 am and 8.00 pm. When we calculate the total time between these two intervals of time, we will get the elapsed time.
Elapsed time is the time that has passed between a specific set of events. In this case, the starting event is Tommy waking up and the ending event is him going to sleep. The elapsed time is the interval between the starting event and the ending event.
Time is always moving forward. Time elapses while doing a task or even while we rest. If we go to school and return in the afternoon, we will notice that several hours have elapsed. Finding the elapsed time on a clock is a very easy task.
Let us try to evaluate the elapsed time in a day when Tommy is awake.
Wake up time: 6.00 am
School time: 7.00 am to 12.00 pm
Piano lessons: 3.00 pm
Playground: 5.00 pm
Dinner: 8.00 pm
Bedtime: 9.00 pm
If we count the total number of +1 hours in all the images, we would get our elapsed time.
So the elapsed time can be calculated as follows:
The elapsed time turns out to be 15 hours. Now, let us see how we solve problems based on elapsed time.
Solved Elapsed Time Examples
Example 1: A summer fair in your town ends in 4 hours. Do you have enough time to spend 15 minutes on each of the 6 rides at the fair?
Solution:
Step 1: Understand the question asked.
What is the information given | What do we need to find? |
|---|---|
The fair ends in 4 hours. | You need to find out whether you have enough time to spend 15 minutes on each of the 6 rides. |
You want to spend 15 minutes on each of the 6 rides. |
Step 2: Plan your calculations.
How will we solve this?
Find the number of minutes until the fair closes.
Then find the total number of minutes it takes to use the 6 rides.
Step 3: Solve and find out the answer.
Part a: We know that there are 60 minutes in an hour.
So, 4 hours will have : 4 \(\times\) 60 minutes or 240 minutes.
So, we have 240 minutes until the fair closes.
Part b: Now, we know that it takes 15 minutes for 1 ride to complete.
So, for 6 rides to be completed, we will require 90 minutes.
So, we have enough time to enjoy all the rides. As there are 240 minutes or 4 hours remaining for the fair to close.
Example 2: A baseball team practices drills for 10 minutes, and then plays a warm-up match for \(1\frac{1}{2}\) hours. The overall practice time is distributed evenly into 4 sessions. What is the duration of each session?
Solution:
Step 1: Find the overall practice time.
The overall practice time is:
= Time spent for drills + Time spent playing a warm-up match
= 10 + 90 minutes (As \(1\frac{1}{2}\) = 1+\(\frac{1}{2}\) hours, which is 60 minutes + 30 minutes)
= 100 minutes.
Step 2: Divide the overall time into 4 sessions.
Let us divide 100 minutes by 4. We get:
So, the duration of each session is 25 minutes.
Example 3: You watch a movie for 150 minutes. There is a 15-minute intermission, and there are commercials that run for 15 minutes. If the overall time spent at the theater is supposed to be divided into three equal parts, how long would one part be?
Solution:
Step 1: Find the overall time spent at the theater:
The overall time spent at the movie theater:
= Movie time + Time taken for the intermission + Time taken to run the commercials.
= 150 + 15 + 15
= 180
Step 2: Divide the overall time into 3 equal parts:
180 \(\div\) 3 =
= 60
So, we can say that the overall movie time can be divided into three equal parts, each 60 minutes long.
Example 4: A group of students attends a concert from 5.30 pm to 8.00 pm. The band in the concert performs 10 songs, and each song is performed for an equal amount of time. For how many minutes was each song played at the concert?
Solution:
Step 1: Find the overall time spent at the concert:
From 5:30 pm to 8:00 pm, the total minutes can be found as
= 60 + 60 + 30
= 150 minutes
Step 2: Divide the overall time by 10:
So, 150 \(\div\) 10 =
= 15 minutes.
So, the band played each song for 15 minutes.
Elapsed time is the time that has passed between an interval of time. For instance, as you were reading this article, time has elapsed.
Finding elapsed time helps us keep track of things and to complete our tasks on time. It also improves qualities such as punctuality and time management skills, which are extremely useful in a person’s life.