Labmanual

UNIT

E x p e r i m e n t 32

AIM

To plot distance – time (s – t ) graph for an object moving with a uniform speed from a given set of s and t data and to determine the speed of the object.

THEORY

A moving object changes its position with time. If the object travels a distance s in time t then its speed is v

s (1) t When an object travels equal distances in equal intervals of time, it is said to have a uniform speed. But if the speed or its direction of motion changes with time then the object is said to be in nonuniform motion. For a uniform motion the distance travelled by the object is directly proportional to time taken. Thus the graph of distance travelled against time is a straight line. This distance-time graph can be used to determine the speed of the object. Fig. 32.1 shows the distance–time (s – t)

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Fig. 32.1 : Distance-time graph of an object moving with uniform speed

Moving Things, People and Ideas

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Laboratory Manual – Science

graph of an object moving with uniform speed. To find the speed of the object consider a small part AB of the s – t graph. The two lines PAC and BCQ drawn parallel to x-axis and y-axis respectively, meet each other at point C to form a triangle ABC. The segment AC denotes the time interval (t2 – t1) while the segment BC corresponds to the distance (s2 – s1). From this graph it can be seen that as the object moves from the point A to point B, it covers a distance (s2 – s 1) in time (t2 – t 1). The speed, v of the object, therefore can be represented as v (2)

1. Examine the given data of distance (s) of the object at different times (t ). Find the difference between the highest Table 1: The motion of a car and the lowest values of each quantity (these are the ranges of the distance and Sl. No. Time, t Distance, s time values.) Table 1 shows the data for (s) (m) the distance travelled by a car (in m) and the time taken (in s) by it to cover that 1. 0 0...