NEET2007PhysicsMotion in One DimensionActual
The position x of a particle with respect to time t along x -axis is given by x=9 t^2-t^3 where x is in metres and t in second. What will be the position of this particle when it achieves maximum speed along the +x direction?
Options
- A54 ~m
- B81 ~m
- C24 ~m
- D32 ~m .
Correct answer
A. 54 ~m
Step-by-step solution
It is given that aligned x & =9 t^2-t^3 v & = d x d t =18 t-3 t^2 d v d t & =a=18-6 t aligned for maximum speed d v d t =0 and d^2 v d t^2 negative So 18-6 t=0 t=3 s at t=3 s, x=9(3)^2-(3)^3=81-27=54 ~m