Physics related

Question

A particle has a velocity u towards east at t=0. Its acceleration is towards west and is a constant, let x and y be the magnitude of displacements in the first 10sefonds and in the next 10 seconds.

(A)x is lesser than y

(B)x is equal to y

(C)x is greater than y

(D)the information is insufficient to decide the relation of x and y

 

Answer 1

The information is insufficient, which is answer (D).  Without knowing the acceleration and initial speed, you cannot tell if the displacement at 20 seconds is greater than, equal to, or less than the displacement at 10 seconds.  For example, the initial velocity u may be very large, causing the object to travel a large distance to the east before the westward acceleration reverses the direction of motion of the object.  Similarly, u could be small and the object has little eastward travel before being reversed.  The magnitude of the acceleration is also relevant, since a strong acceleration to the west can quickly overcome the initial speed to the east, or a weak acceleration to the west takes a long time to reverse the direction of the object.  With numbers for acceleration and initial speed, we could find exactly when and where the object turns.