Question

A particle returns to the starting point after $10s$. If the rate of change of velocity during the motion is constant in magnitude, then its location after $7$ seconds will be same as that after: (in seconds)

• A. $2$
  
• B. $3$
  
• C. $4$
  
• D. $5$
  

Answer 1

Answer: (B)

$3$

this is the case when velocity and acceleration of the body both are in opposite direction so body will first moves in direction of velocity and then will move in direction of acceleration.

in the given question it is said that body returns to initial position after 10 sec.[this case can be treated same as motion of body in vertical direction with constant acceleration downwards and thrown upward initially]

means velocity of body will be zero at 5 sec.

displacement will be symmetric about the zero velocity time so will be at same position at time 3 sec which will be at 7 sec.

so best possible answer is option B.