What is meant by Motion and Time

Introduction looks around yourself, and you will find objects of different kinds such as television mobile trees cars buses trains etc. objects such as television mobile trees etc. are static in other words their position does not change with time such objects are said to be at rest whereas objects such as cars buses trains etc. are non-static it means that their position changes with time such objects are said to be in motion let us discuss motion and time in greater detail in this lesson objectives at the end of this lesson you will be able to differentiate between slow and fast motions define speed measure speed identify the units of speed measure time suppose you have an appointment with your doctor at five in the evening it is already 4 30 pm and the doctor's clinic is 5 kilometers away from your house you have the choice of either cycling down or taking a taxi to the clinic what will you do correct you will take a taxi because a taxi is faster than a cycle, so we can say that some objects move faster than others now the same taxi moves fast on an empty road and slow on a busy road thus the same object can move fast at one time and slow at another time the next step is to identify whether an object is moving faster or slower than another object to do that you must calculate the distance covered by both the objects in the same time interval consider a thousand-meter cycle race when the whistle blows the race begins every cyclist starts at the same time suppose after 10 minutes one cyclist reaches the finishing line this means that the winner covered the distance of 1000 meters in 10 minutes this also means that all the others who reached the finishing line later covered less than 1 000 meters in 10 minutes and hence lost the race, so we can say that the object that covers a longer distance in a given time interval than other is faster the most convenient way of finding out which object moves faster than the others is to calculate and compare the distances covered by all the objects per unit time the object that covers a greater distance per unit time is quite obviously faster the distance covered by an object per unit time is called the speed of the object suppose your brother claims that his motorbike is faster than his friends his friend denies you know that your brother's motorbike covers a distance of 60 kilometers in an hour whereas his friend's bike covers 40 kilometers in one hour let us now check the claims of your brother and his friend the speed of your brother's bike is 60 kilometers per hour and that of his friend's bike is 40 kilometers per hour your brother's bike is certainly faster than his friends because its speed is greater to measure the speed of an object we measure the distance covered and time taken to cover that distance by the object after that we apply formula of speed let us learn to measure speed with this simple exercise draw a line ask a friend of yours to stand on the line allow him to run till he wants to stop note the total time taken from the moment he started to the moment when he stopped measure the distance covered by your friend now divide the distance covered by the time taken to cover the distance what you have calculated is the running speed of your friend do the meters and indicators in front of the driver's seat of your father's car scare you now they won't straight beyond the steering wheel are two meters the circular dial which looks somewhat like a clock with needles and numbers is the speedometer when the car is in motion one needle points to a particular number in the speedometer this number is the speed of the car in kilometer per hour there is also a rectangular box within a speedometer that has digits written on it when the car is in motion these digits undergo a change rather increase this rectangular box is known as the odometer its readings show the distance covered by the car have you ever wondered how our elders could tell the approximate time of the day by just looking at the shadows many events in nature repeat themselves after definite intervals of time for example sun rises every day in the morning the time between one sunrise and the next is called a day similarly a month is measured from one full moon to the next one year is the time taken by earth to complete one revolution of the sun to measure intervals of time which are shorter than a day we use clocks and watches the basic unit of time is second its symbol is s larger units of time are minutes and hours one minute is equal to 60 seconds and 60 minutes are equal to one hour the basic unit of speed is meter per second we can also express it in other units such as meter per minute and kilometer per hour we write the symbols of all units in singular summary let us summarize what we have learned some object moves faster than others the object which covers larger distance in a fixed time interval move faster than other the distance covered by an object per unit time is called the speed of the object speed is measured in kilometer per hour or meter per second speedometer measures the speed of a vehicle and odometer shows the distance covered by it