If s=2t3-6t2+at+5 is the distance travelled by a particle at time t and if the velocity is - 3 when its acceleration is zero, then the value of a is

Question

If s=2t3-6t2+at+5 is the distance travelled by a particle at time t and if the velocity is - 3 when its acceleration is zero, then the value of a is (A) - 3 (B) 3 (C) 4 (D) - 4

Tardigrade Admin · Accepted Answer

Given, s=2 t3-6 t2+a t+5 Velocity, V=(d s/d t)=6 t2-12 t+a Acceleration, A=(d2 s/d t2)=12 t-12 Since, A=0 ⇒ 12 t-12=0 ⇒ t=1 At t=1, V=6-12+a=a-6 It is given that, at A=0, V=-3 ⇒ a-6=-3 ⇒ a=3

Q. Ifs=2t3−6t2+at+5 is the distance travelled by a particle at time t and if the velocity is −3 when its acceleration is zero, then the value of a is

- 3

3

4

- 4

2

Given, s=2t3−6t2+at+5 Velocity, V=dtds​=6t2−12t+a Acceleration, A=dt2d2s​=12t−12 Since, A=0 ⇒12t−12=0 ⇒t=1 At t=1, V=6−12+a=a−6 It is given that, at A=0,V=−3 ⇒a−6=−3 ⇒a=3

Q. $I f s = 2 t^{3} - 6 t^{2} + a t + 5$ is the distance travelled by a particle at time $t$ and if the velocity is $- 3$ when its acceleration is zero, then the value of $a$ is