Question

If a particle ‘s motion is described as x= ut + 1 2 a1t 2 , where x is position , t is the time and u and a1 , are constants . Show that acceleration of the particle is constant . no copying from, meritnation or google

Answer 1

Given that,

x=9t  

2

−t  

3

.....(I)

We know that,

v=  

dt

dx

​  

 

The maximum speed is

v=18t−3t  

2

 

v maximum, at  

dt

dv

​  

=0

dt

dv

​  

=18−6t

The time will be

0=18−6t

t=3 sec

The position of the particle at 3 sec

Put the value of t in equation (I)

x=9×9−27

x=81−27

x=54 m

The position of the particle will be 54 m.

Hence, Option A is correct