The Total solution for NCERT class 6-12
A three-wheeler starts from rest, accelerates uniformly with 1 m s–2 on astraight road for 10 s, and then moves with uniform velocity. Plot the distancecovered by the vehicle during the nth second (n = 1,2,3….) versus n. What doyou expect this plot to be during accelerated motion: a straight line or aparabola?
For a straight line,the distance covered by a body in nth second is :SN = u + a (2n – 1)/2 . . . . . . . . ( 1 )Where,
a = Acceleration
u = Initialvelocityn = Time = 1, 2, 3, . . . . . , nIn the above case,a = 1 m/s2 and u = 0.∴ SN =(2n – 1) / 2 . . . . . . . . . . .( 2 )This relation shows that:SN ∝ n .. . . .. . . . . ( 3 )
Now substitutingdifferent values of n in equation ( 2 ) we get:
n
1
2
3
4
5
6
7
8
9
SN
0.5
1.5
2.5
3.5
4.5
5.5
6.5
7.5
8.5
This plot is expectedto be a straight line.