(i) Computers are used in various fields.
(ii) In textile shop it is used for billing.
(iii) Computers are used to control large and small machines.
(iv) Computers are most important educational tools for teachers and learners.
(v) In Railways it is useful to book tickets and for other purposes.
(vi) It is also used in banks, ATM's, Post offices and in many places.
(vii) We can save many data and convert it into information.

Linear motion - A coconut falling from a tree
Curvilinear motion - A car driving around a curve
Self rotatory motion - Motion of the wheel in a cart
Circular motion - Athlete running around a track
Oscillatory motion - Swinging of a pendulum
Irregular motion - Movement of people in a bazaar

Method 1:
(i) Place a string along the curved line, Make sure that the stringcovers every bit of the curved line.
(ii) Mark the points where the curved line begins and ends on the string.
(iii) Now, stretch the string along the length of a meter scale and measure the distance between the two markings of the string.
(iv) This will give us the length of a curved line.
Method 2:
(i) Draw a curved line AB on a piece of paper.
(ii) Separate the legs of the divider by 0.5 cm or 1 cm using a ruler.
(iii) Place it on the curved line starting from one end. Mark the position of the other end. Move it along the line again and again cutting the line into number of segments of equal lengths. The remaining parts of the line can be measured using a scale.
(iv) Count the number of segments.
(v) Therefore, the length of the line = (number of segments x length of each segment) + length of the left over part.