Question

What will be the answer?

. A train is moving forward at a velocity of 2.0 m/s. At the instant the train begins to accelerate at 0.80 m/s2, a passenger drops a quarter which takes 0.50 s to fall to the floor. Relative to a spot on the floor directly under the quarter at release, it lands:
(A) 1.1 m toward the rear of the train.
(B) 1.0 m toward the rear of the train.
(C) 0.10 m toward the rear of the train.
(D) directly on the spot.
(E) 0.90 m toward the front of the train.

Answer 1

Option `C` is the answer

Explanation:

Due to inertia of motion the quarter at the time of its release will have same velocity as that of the train i.e.`2m"/"s`. As the time of fall is `0.5s` it will move `2xx0.5=1m` towards the front of the train during its time of flight.

But the train will move with acceleration `0.8ms^-2` and will move during the time of fall of the quarter by the distance `=2xx0.5+1/2xx0.8xx(0.5)^2=1.1` m
Hence the quarter will fall `0.1m` toward the rear of the train relative to the spot directly under the quarter at release.

Option `C` is the answer