If you wanna calculate the time taken by an object to travel a certain distance at a given speed then this article is going to be of great help to you. By the end of this page, you will be familiar with many details such as What exactly is time, its units, what is the formula to find time, steps to follow to find the time when distance and speed are given.
Usually, Time and Speed have an Inverse Relationship i.e. if one increases the other decreases. Know how this is applicable by going through our problems on calculating time in the below modules. Try to answer the Time Speed and Distance Questions over here and know what kind of questions you might come across in your exams.
Do refer to similar articles:
What is the Formula to Find Time?
The mathematical equation stating the Relationship between Speed, Distance, and Time is given by the expression Speed = Distance/Time
Rearranging the above basic formula we can get the formula for Time i.e. Time = Distance/Speed
Units of Time
Time uses three units in most common and they are namely Hours, Minutes, Seconds. To know in detail other units you can check out our other articles on Units of Time.
Problems on Calculating Time
Example 1.
Two trains 120 m,100 in length are running in the same direction. The first runs at the rate of 60 km/s and the second rate at the rate of 45 m/sec. How long will they take to cross each other?
Solution:
Given,
Length of first train=120 m
Length of second train=100 m
Speed of first train=60 m/s
Speed of the second train=45 m/sec
Relative speed=60-45=15 m/sec
Since trains are running in the same direction
As per the formula, L1 +L2/x-y
=120+100/15=220/15
=14.66 seconds
Hence, two trains will take 14.66 seconds to cross each other.
Example 2.
Two trains, 90 m, 100 m in length running in the opposite direction. The first runs at the rate of 20 m/sec and the second runs at the rate of 30 m/sec. How long will they take to cross each other?
Solution:
Given that, Length of the first train=90 m
Length of the second train=100 m
Speed of the first train=20 m/sec
speed of the second train=30 m/sec
Relative speed=30+20=50 m/sec
Since trains are running in the opposite directions,
As per the formula, L1+L2/x+y
=90+100/50
=190/50=3.8 seconds
Hence, two trains would take 3.8 seconds to cross each other.
Example 3.
Sandeep walking his 2/5 of his usual speed reaches the temple 15 min late. Find his usual time to reach the temple?
Solution:
Given that,
new speed a/b is=2/5
change in time=15 min
Usual time to reach the temple=?
As we know the formula, usual time=change in time/(b/a-1)
=15/(5/2-1 )
=15 × 2/3
=30/3=10 min
Hence, Sandeep’s usual time to reach the temple is 10 min.
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Example 4.
A train 300 m long has a speed of 20 m/sec. How long will it take to pass a platform of length 60 m?
Solution:
Given,
Length of the train=300 m
Speed=20 m/sec
The distance here will be the same as the length of the train and the length of the platform.
=300+60=360 m
Therefore, time=360/10=36 seconds.
Example 5.
Amrutha and Sudha have to travel from Hyderabad to Vijayawada in their respective cars. Amrutha is driving at 50 Kmph while Sudha is driving at 100 km per hour. Find the time taken by Sudha to reach Vijayawada if Amrutha takes 10 hours?
Solution:
Given,
Amrutha driving speed=50 km per hour
Sudha driving speed=100 km per hour
Here distance is the same. Time taken is inversely proportional to speed.
Speed of Amrutha and Sudha is in the ratio 50:100 or1:2
So that ratio of time taken by Amrutha to that time taken by Sudha will be in the ratio 2:1.
So if Amrutha takes 10 hours, Sudha takes 5 hours.
Hence, Time taken by Sudha to reach Vijayawada is 5 hours.
Example 6.
A train 200 meters long has a speed of 20 m/sec. How long will it take to pass an electric pole?
Solution:
Given,
Length of the train=200 meters
Speed=20 m/sec
We know that time=distance/speed
The distance here will be the same as the length of the train. i.e. 200 meters.
Therefore, Time=200/20=10 seconds.
Hence, it will take 10 seconds to pass an electric pole.
Example 7.
Anil has to attend the dancing class which is 800 meters away. He is walking at the speed of 1.5 ms. How long will it take to get to class?
Solution:
Given,
Anil has to walk a distance=800 meters
walking speed=1.5 ms
time=?
We know that time=distance/speed
=800/1.5=533.33
Hence, Anil will take 533.33 sec to attend the dance class.
Example 8.
Avinash takes 5 hrs 30 min in going by cycle and comes back by scooter. He would have lost 2 hrs 10 min by going on cycle both ways. How long would it take him to go by scooter both ways?
Solution:
Given,
Avinash takes time in going by cycle and comes back by scooter=5 hrs 30 min
Avinash will lose time by going on cycle both ways=2 hrs 10 min
Time taken by Avinash to go by scooter both ways= 5 hr 30 min-2 hrs 10 min
=3 hr 20 min=3 1/3 hrs.
Hence, Avinash will take 3 2/3 hrs to go by scooter both ways.