Question

9. Figure (3-E4) shows the graph of the x-coordinate of a
particle going along the X-axis as a function of time.
Find (a) the average velocity during 0 to 10 s,
(b) instantaneous velocity at 2, 5, 8 and 125.
4x (m)
100+
50+
Time (second)
2.5
5.0
7.5
10.0
12.5
15.0
Figure 3-E4​

Answer 1

Answer:

(a) Displacement during 0 to 10 s = x = 100 m,    Average velocity during 0 to 10 s = 100 m/ 10 s = 10 m/s 

(b) Instantaneous velocity at n second,  vn is given by the slope of the graph at that instant   

v2 = slope of st line at 2s = 50/2.5 = 20 m/s  

v5 = slope of st line at 5 s = zero    

v8 = slope of st line at 8 s = (100-50)/(10-7.5) =50/2.5 =20 m/s  

v12 = slope of st line at 12 s = -100/5 =-20 m/s  (because slope is negative)