Verified Solution • 2025–26 Session moderate

QNEET-2018-Ph-904: NEET 2018 Physics - Class 12 NEET-2018-Ph-904 Solution: A toy car with charge q moves on a frictionless horizontal…

A toy car with charge q moves on a frictionless horizontal plane surface under the influence of a uniform electric field E⃗\vec{E}. Due to the force qE⃗q\vec{E} its velocity increases from 0 to 6 m s−1s^{-1} in one second duration. At that instant the direction of the field is reversed. The car continues to move for two more seconds under the influence of this field. The average velocity and the average speed of the toy car between 0 to 3 seconds are respectively 2 m s−1s^{-1} 4 m s−1s^{-1} 1 m s−1s^{-1} 3 m s−1s^{-1} 1 m s−1s^{-1} 3.5 m s−1s^{-1} 1.5 m s−1s^{-1} 3 m s−1s^{-1}

Multiple Choice Options

  • A 2 m s �1 , 4 m s �1
  • B 1 m s �1 , 3 m s �1
  • C 1 m s �1 , 3.5 m s �1
  • D 1.5 m s �1 , 3 m s �1

Step-by-Step Verified Solution

Acceleration, a = v _ u t = 6 _ 0 1 = 6 ms -2 For t = 0 to t = 1 s, S 1 = 1 2 _ 6 ( 1 ) 2 = 3 m ...(i) For t = 1 s = to t = 2 s, S 2 = 6.1 - 1 2 _ 6 ( 1 ) 2 = 3 m ...(ii) For t = 2 s to t = 3 s, S 3 = 0 - 1 2 _ 6 ( 1 ) 2 = -3 m ...(ii) Total displacement S = S 1 + S 2 + S 3 = 3 m Average velocity = 3 3 = 1 ms -1 Total distance travelled = 9 m Average speed = 9 3 = 3 ms -1

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