# Speed

In a race only one athalate who runs/drives faster than other can win. This indicates that though some objects are moving along same path, they takes different time for completing the motion over the same path. Why does it happen? The answer is, all objects/athalates/vehicles has different speeds. So what is speed? Lets learn it.

Observe the diagram given below. Imagine an object starts his motion from point A, then goes to point B, point C and finally stops at point D. Let d1, d2 and d3 be the distances travelled during this motion with t1, t2 and t3 be the corresponing time required for the motion. Then the total distance travelled by object can be given as, d = d1 + d2 + d3   and total time required is t = t1 + t2 + t3

Speed of a body is define as the distance travelled by object during motion in a specific time. i.e. distance travelled per unit time is called as speed. Denoted by ‘v’ We measure distance in meter and time in second, then SI unit of speed can be given as , meter/second (m/s  or m. s-1) read as meter per second.

In a simple way suppose an athalate runs 400 meters in 10 seconds, then

Speed of the athalate is, Q. What do you mean by speed?

Ans: Speed of a body is define as the distance travelled by object during motion in a specific time.

Q. State Si unit of speed.

Ans: meter/second

Q. State the basic formula for speed.

Ans: speed = distance/time.