 # Motion and Measurement  View Notes

### Introduction

Wherever there is change in position of the object or body we termed it as motion, as they are continuously changing their initial position with respect to time. But when an object or body is not changing its position with respect to time it is said to be in rest position. Example of a rest position is a pen kept on table and for motion is walking on a road.  Whereas the case of measurement has different concepts with respect to motion. In the case of measurement  we quantify objects or anything. Example: distance of your school from your home.

### What is Motion?

Whenever there is movement or change in position of an object or body we termed it as motion.

Example: Moving train, flying aeroplane, etc.

We can classify motion into various types:

1.Rectilinear Motion: When an object moves along a straight line it is called rectilinear motion. Example: person walking on a straight road.

2.Circular Motion: When the distance of the object from a fixed point remains constant, it possesses circular motion. Example: object moving around a circular well.

3.Periodic Motion: When an object moves to and fro about a point it possesses periodic motion.

Example: moving pendulum.

### Measurement of Distance with respect to Time

As distance is measured with respect to time we denote it as (T) in dimensional formula.

If in case speed if an object is given and time is also given then from here we can find distance covered by moving objects.

As  distance = speed/ time

In terms of S.I unit Meter = Meter per second / Second

So from here we can find a covered distance.

S.I unit of distance is Meter and in dimensional formula we consider S.I unit as dimensional formula is written in the form of (MLT). Here M stands for mass, L stands for length/distance and T stands for time.

### Story of Transportation

There is a long story behind transportation. Earlier people used to move only on foot and carry their goods either on their back or by using animals. Whereas for transport along waterways they used boats. Simple wood logs were used for boat formation and they use wood with hollow cavities inside it, so that wood can float on water streams. Slowly and gradually people started learning how to give different shapes to boats. By passing time they invent wheels, which become a grat mode for transportation. Upto 19th century people were totally dependent on animals for transportation purposes. But by the end of the 19th century steam engines were invented which became a great source of power. After this people keep on inventing different modes of transportation.

### Measurement History

In ancient times, the length of foot, the width of finger and distance between two different places were commonly measured by different units of measurements.

This was proved by people of Indus valley civilization as because of their good measurement as constructed such a good  geometrical monument. Where in ancient Egypt they used cubits from elbow to fingertips and this was accepted as a length all over the world. In some parts of the world people also use feet as a unit of length.

### Standard Unit of Measurement

For unique measurement properties, scientists accepted standard units of measurement all over the world. As this unit is now known as the international system of unit i.e (S.I Units). Each different fundamental quantity has different S.I units. S.I unit of length is meter. Each meter is divided into 100 equal divisions known as centimeters(cm). Further each centimeter has 10 equal divisions known as millimeters(mm).

1 meter = 100 centimeter

1 centimeter = 10 millimeter

1 kilometer = 1000 meter

### Zero Error and Correct Way to Measure Length

We use different instruments for measurement of different objects depending upon their shape and size. Different ways are there for accurate measurement of an object. Some of these tips are given below:

1. Scale should be in proper contact with the object which is being measured.

2. If the scale is broken or the zero mark is not visible then we have to take different points as a zero point for proper measurement of an object.

3. Your eye should be exactly above the point, where measurement is to be taken.

4. We will get correct reading if we subtract the value from the full mark considered as zero.

### How to Measure a Curved Line

Measurement of curved line can be done by following method:

1. It is not possible to measure the length of curves by meter scales.

2. So for measurement of curved line string is used by creating a knot at one end and keeping at the beginning. By this we can measure its length.

3. After this we have to stretch the length of the string and measure it with the help of meter scale.

4. Measuring tape can also be used for the measurement of curved objects. Example: length of snake, length of curved landscape, etc.

1. What is Motion?

Whenever there is movement or change in position of an object or body we termed it as motion.

Example: Moving train, flying aeroplane, etc.

2. Explain different Types of Motion?

Mainly there are three different types of motion, they are:

1. Rectilinear Motion: When an object moves along a straight line it is called rectilinear motion. Example: person walking on a straight road.

2. Circular Motion: When the distance of the object from a fixed point remains constant, it possesses circular motion. Example: object moving around a circular well.

3. Periodic Motion: When an object moves to and fro about a point it possesses periodic motion. Example: moving pendulum.

3. What is Parallax?

Parallax is the displacement or the change in the apparent position of the object when viewed from two different points of views. This type of error while measuring is called a parallax error.

4. What is the Standard Unit of Measurement?

It is now known as the international system of unit i.e (S.I Units). Each different fundamental quantity has different S.I units.

S.I unit of length is meter.

1 meter = 100 centimeter

1 centimeter = 10 millimeter

1 kilometer = 1000 meter

Fundamental and Derived Units of Measurement  Measurement of Length Distance  Temperature Measurement - Thermometer  Measurement of Mass and Weight  Uniform Motion and Non Uniform Motion  Motion and Time  Horizontal Motion  Dynamics of Circular Motion  Newton's Second Law of Motion  Motion of Celestial Bodies in Space  