Question

3.
A particle is moving in a straight line with the relation between the time and distance in such a
way that s = t3 – 9 t2 + 24t – 18. Then the value of its velocity when its acceleration is zero is
a) 3 units
b)-3 units
c) 6 units
d) -6 units
​

Answer 1

Answer:

-3

option d

first) differentiate s=..... then we would get

3t2-18t+24=velocity......1

then differentiate it again

then, we will get

6t-18=acceleration

given acceleration=0

6t-18=0

6t=18

t=3

substitute t=3 in 1

27-54+24=vel

vel=24-27

velocity= -3