Q.

In some appropriate units, time (t) and position (x) relation of a moving particle is given by t=x2+x. The acceleration of the particle is:           [2025]

1 +2(x+1)3  
2 +22x+1  
3 -2(x+2)3  
4 -2(2x+1)3  

Ans.

(4)

Given, t=x2+x

Differentiating with respect to 't' on both sides,

dtdt=2xdxdt+dxdt

1=2xv+v                                  ...(i)

1=v(2x+1)

         v=12x+1                                 ...(ii)

Again, differentiating equation (i) with respect to 't',

0=2(dxdt.v+xdvdt)+dvdt

0=2(v2+x.a)+a

0=2v2+2xa+a

0=[2v2+a(2x+1)]

2v2=-a(2x+1)

Using equation (ii), we get

2(12x+1)2=-a(2x+1)

   a=-2(2x+1)3