Ncert Exercises & Solutions

4.23 For any arbitrary motion in space, which of the following relations are true :

(a) vaverage = (1/2) (v (t1) + v (t2))

(b) vaverage = [r(t2) - r(t1) ] /(t2 – t1)

(d) r (t) = r (0) + v (0) t + (1/2) at2

(e) a average =[ v (t2) - v (t1 )] /( t2 – t1)

(The ‘average’ stands for average of the quantity over the time interval t1 to t2)

NEETprep Answer:

(b) and (e) are true; others are false because relations (a), (c), and (d) hold only for uniform acceleration.