The motion of a particle along a straight line is described by equation
 x=8+12 t -t³
where x is in metre and t in second. The retardation of the particle when its velocity becomes zero, is

• 24 ms^-2

• zero

• 6 ms^-2

• 6 ms^-2

The force F acting on a particle of mass m is indicated by the force-time graph as shown below. The climate change in momentum of the particle over the time interval from zero to 8 s is,

• 24 Ns

• 20 Ns

• 12 Ns

• 12 Ns

A ship A is moving Westwards with a speed of 10 kmh^-1 and a ship B 100km  south of A, is moving Northwards with a speed of 10 kmh^-1. The time after which the distance between them becomes shortest is

• 0 h

• 5 h

• 
• 

A stone falls freely under gravity. It covers distances h₁ , h₂ and h₃ in the first 5 seconds, the next 5 seconds and the next 5 seconds respectively. The relations between h₁, h₂ and h₃ is,

• h₁ = 2 h₂ = 3 h₃

• h₁ = 

• h₂ = 3 h₁ and h₃ = 3 h₂

• h₂ = 3 h₁ and h₃ = 3 h₂

A particle is moving such that its position coordinates (x,y) are (2m, 3m) at time t = 0, (6m, 7m) at time t = 2 sec and (13 m, 14m) at time t= 5 sec. Average velocity vector (v_av) from t = 0 to t = 5 s is,