Hello everyone, welcome back to another video In today's
video, which topic are we going to start?
We are going to start the topic of Speed, Time and Distance
Speed, Time and Distance
Although this topic comes in Science
But in this, the calculation comes in Aptitude also
We can do calculation using Mathematics
So, there is nothing to worry about
If this is a science topic, then how will commerce students
do?
Speed, Time, Distance
This is known in everyone's life Nowadays, everyone is
driving a vehicle
Everyone knows that how many km per hour we are going
What is the unit of speed?
Or what is the unit of distance? Or what is the unit of
time?
This is a basic concept which everyone knows So, there is
nothing to worry about This is a science topic
This is not a science topic This is a very important topic
of Aptitude Time, Speed and Distance
Or your next topic will be related to time and work
So, the questions on this topic are asked in every
competitive exam
Or in every aptitude exam
So, let's start
First of all, we will know about these three words
Time, Speed and Distance
What are they?
What is their unit?
The main thing we should know is
What is their unit?
Now, you will ask what is unit?
Unit means what do we measure them in?
For example, we have time
We measure time in minutes, seconds, hours
We measure in this and tell in this
Or how many days have passed
We convert the days into hours
Then we cut it down in minutes
We do like this
Similarly, we calculate the distance
What is the unit of it?
In which we are calculating it?
For example, if I say 5
If I have to tell the distance 5
What will we put in front of 5?
We will know that it is distance
So, we will have to put a unit for distance
As soon as we say it, we will know
That what I am saying is distance If I say 5 km
Similarly, we should know that we are talking about distance
If I say 5 minutes
As soon as we see this unit, we should know
That we are talking about time
Similarly, there is a unit of speed
You all know the unit of speed Km per hour We say it in km
per hour Mostly, we say it in km per hour in normal language
But the other unit of it is meter per second
So, we will use two units Mostly, the standard unit
One is the speed unit
Km per hour
One unit is the speed unit
And the other unit is meter per second
So, we will read their questions in two units
One is km per hour and the other is meter per second
Now, you have to remember the formula of distance, speed
and time
Which you can easily remember
You can remember it by looking at this unit For example,
what is speed?
Its unit is km per hour
And what do we measure in km? It is distance
We will measure distance in km
So, what will be the formula of speed?
Speed is equal to km
It is used for distance
So, distance per hour
So, how do we calculate per?
In fraction
And per hour, what is the unit of hour?
It is the unit of time
So, what is the unit of hour? It is the unit of time
So, distance upon time
Now, we have the formula of speed
That is speed is equal to distance upon time
You don't have to focus on this topic You have to focus on
units
That your units should be same in all the questions
And the most important thing is
You have to focus on this formula This formula is the base
of this concept
This formula will be used in all the questions related to
speed
You can use this formula for distance
What will be the distance?
Distance is equal to speed into time Time will be
multiplied with speed
Similarly, if we want to find out the time
So, what will be the time?
Time is equal to distance upon speed
So, we will subtract all three from this formula
So, the first unit that we did
If we have distance in kilometer
So, for that we should have time in hours So, our speed
will be in kilometer per hour
But, if we have distance in meter So, suppose we have given
time in hours So, will we subtract meter per hour? No, we
will not subtract meter per hour In that we will do
conversion
Either you will change this meter in kilometer
And will keep time in hours
So, unit will be kilometer per hour
But, if you are not changing meter So, what you have to
change?
You have to change time
You have to convert from hours to minutes
Because we have standard unit only
So, we have kilometer per hour
And hour per kilometer
And meter per second
This should be in your mind In this way, we will learn unit
conversion So, I hope you all remember this formula It is
just a matter of one second
So, you should remember this formula
Now, we will learn how to convert units
So, next we will learn conversion of units
First of all, you all know that
If we want to change one kilometer in meters
So, what is the relation?
One kilometer is equal to thousand meters
You all know that how many meters are there in one
kilometer?
It is thousand meters
If we see the conversion of time
In one hour, how many minutes are there?
It is sixty minutes
But, how we have to convert hour?
It is meter per second
So, if we have distance in meters
So, for that, what should be the time?
It should be in seconds
So, we have taken out minute speed from hour
So, how we will change this further?
We will change this further in seconds
So, one minute is equal to sixty seconds
So, here we have to take out sixty minutes
Because, we have to see one hour
How many seconds are there in one hour?
So, in sixty minutes, what will be the time?
It is sixty into sixty seconds
That is thirty six hundred seconds
So, in sixty minutes, what else we can write?
We can write one hour
So, one hour is equal to thirty six hundred seconds
So, one kilometer is equal to thousand meter
And one hour is equal to thirty six hundred seconds
This is our simple
But, if we have any x kilometer per hour If we have any
speed
Speed is a unit of kilometer per hour This is some speed
It can be anything
We have taken x kilometer
In general, any arbitrary x kilometer per hour
If we have to change this
In what we have to change this? We have to change this
speed in meter per second
So, how will we change?
If we have to change this speed in meter per second So, how
will we do?
So, I will tell you how we will do
So, write what is our speed? Speed is five Sorry, five is a
particular number We have taken x kilometer per hour
What does it mean?
Our speed is x kilometer per hour Means, we are covering x
kilometer distance in one hour
If we change this Similarly, if we see word wise, then x km
covered means x km distance covered in 1 hour.
If we see in meter per second, then how many meters we have
to cover in 1 hour.
If we change 1 hour in 3600, then how will we change x km?
First of all, you change x km in meter.
When 1000 meter is in 1 km, then how many meters will be in
x km? x into 1000, x into 1000 meters, that is 1000x meters.
So, how many meters will be in x km? 1000x meters.
So, we can write x km as 1000x meters.
Covered in, I am just changing it, instead of x km, I am
writing it in meter.
Similarly, we will write 1 hour in second.
We know 1 hour.
Now, why I have taken 1 hour here?
Because per hour, I am telling about 1 hour.
In 1 hour, you can cover x km distance.
So, 1 hour covered in, if we change it in seconds, then how
much will it be? 3600 seconds.
So, 1000x meters covered in 3600 seconds.
Now, you can apply speed formula in this.
This is distance, this is in meters.
This is distance, this is time.
So, what will be the speed?
Distance upon time, that is 1000x upon meters upon 3600
seconds.
So, now the speed we will get, that would be in meter per
second.
Its unit will be meter per second.
Now, you cancel out this in short, in lowest form, 0000
cancel.
What will be this?
Going from 2's table, 2 5's and 2 18's.
So, what will be this? 5 by 18 meter per second.
And, the initial speed we had, what was the initial speed?
x km per hour.
So, this is x.
So, suppose if we have given x km per hour speed, we have
to change it in meter per second.
So, we just have to do that speed.
We had given speed x, so we don't have to do anything.
We have to multiply given speed by what?
Given speed is x, so we have to multiply given speed by 5
by 18.
As soon as we multiply it by 5 by 18, so we will have unit
change, from km per hour, what will be the speed unit?
Meter per second.
And, you can use this vice versa also.
How vice versa?
If you are given in meter per second, in which speed you
are given?
Meter per second.
But, you have the requirement of the question, that you
have to give the answer in km per hour.
So, what you will do?
If you have to multiply 5 by 18, then take it there.
So, what will happen there?
It will become 18 by 5.
So, whatever speed you are given in meter per second,
multiply it by 18 by 5, and it will come in r per second.
So, we will write it.
How will we write?
If your speed is, we are talking about speed only,
Speed, if it is given in km per hour, if you have to change
it in meter per second, in meter per second, so, if it is
suppose x km per hour, then you have to multiply that speed
by, 5 by 18 into x, whatever speed you are initially given.
And, if you have to go vice versa, in meter per second,
suppose you are given, x meter per second speed, if you
have to do it in km per hour, then you have to multiply it
by, 18 by 5, into the speed you are given, initial speed,
and it will become, km
per hour. This much conversion, I hope it will be clear to
everyone.
In this, we have used maths for kids,
Unit 3 method, which we use in childhood.
If you know 1 toffee, then take out 10 toffees.
In the same way, we have used the same method, and nothing
else. Let's see a question on this.
This is your question.
Read it once.
What is written in the question?
A runner can complete a 750 meter race,
A runner can complete a 750 meter race, in 2 and a half
minutes.
In 2 and a half minutes, what is the distance he is
covering? He is covering 750 meters.
What is the distance he is covering? He is covering 750
meters.
Will he be able to beat another runner, who runs at a speed
of, at, speed of is not written, but you can understand, km
per hour is given.
So what will happen?
If it is given in this unit, km per hour, then it will be
speed.
So this is the speed of the second runner, 17 km per hour.
Now see, if you are of this runner, how will we be able to
tell, whether he will be able to reach faster or later?
We will be able to tell by comparing his speed, that he
will reach earlier on time. The one whose speed will be
more, will reach faster.
The one whose speed will be less, will reach later.
So what do we have to find out?
We have to find out his speed.
Now the speed of the second runner is already given, 17 km
per hour.
It is already given.
So see the unit of this, km per hour. This is the speed of
the second runner.
Color change.
So what is the speed of the second runner? 17 km per hour.
We have to find out the speed of the first runner, whose
speed we have been told.
So for that, we have been given the distance, 750 meters.
So what is the distance?
The distance is 750 meters.
And what is the time given? 2.5 minutes.
So we have the time.
The time is 2.5 minutes.
Now, whenever we are given the distance in meters, then in
what should we convert the time?
It should be in seconds.
But what is the time here?
It is in minutes.
So what do we do first?
First we convert it in seconds.
So convert it in seconds.
So what is this? 2 minutes.
How can we write 2.5 minutes?
We can write it as 2 minutes, plus half minute means 30
seconds.
2 minutes 30 seconds.
Now change the minute.
If 1 minute has 60 seconds, then how many seconds will 2
minutes have? 60 plus 60? 120.
So this is 120 plus 30 seconds.
So what is the total? 150 seconds.
So what is 2.5 minutes?
It is 150 seconds.
So we have the distance and time.
Now take out the speed of the first runner.
Let's give it a name, first runner.
Distance upon time.
Distance is 750 meters.
And time is 150 seconds.
So what is this?
Cancel out.
This is the speed.
5 meters per second.
So what is the speed of this? 5 meters per second.
And the speed of the second runner was 17 kilometers per
hour.
So meter per second and kilometer per hour.
You are not able to compare them.
Who will reach first?
First we will have to make the unit of both of them same.
Only then we will be able to compare.
So what should we do first?
Either you change this to kilometer per hour.
Or change this to meter per second.
If we are changing this to meter per second.
Then what will happen?
Speed 17 km per hour.
What we have to do to go from km to m per second?
We have to multiply 5 by 18.
So do this.
17 into 5 by 18 km per second.
You will not understand that 17 by 18 will be less than 1.
It will be less than 1.
If we multiply it by 5, we will get less than 5.
Now it will be tough for you to see that this is small and
this is big.
So I will tell you with another method.
What can you do with another method? You can convert this 5
m per second into km per hour.
So what do we have to do to convert this into km per hour?
We have to multiply 18 by 5 by its reciprocal.
So 5 into 18 by 5 km per hour.
5 by 5 cancels and we get 18 km per hour.
So the speed of first runner is 18 km per hour.
Whereas the speed of second runner is 17 km per hour.
So this 17 km distance is covered in an hour and this is 18
km.
So this is covering more distance because its speed is more.
So who will be able to finish the race first?
Obviously our first runner.
So what will happen to our first runner?
Will he be able to beat another runner?
Yes, he will be able to beat another runner.
Because his speed is more than the speed of second runner.
So this was the question of conversion.
So this was the basic speed formula and unit conversion.
In the next video, we will learn about other speeds.
Like average speed or relative speed and questions based on
that.
Till then you just watch the unit conversion and formula.
Thank you for watching the video.
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