2002 · Q40
Assertion (A)A train has come out of the platform and is accelerating. If a person sitting in the train and facing engine, throws up a coin, it will fall ahead of him.
Reason (R)A force acts on the coin whose magnitude is equal to the product of the mass of the coin and acceleration of the train.
Select the correct answer using the codes given below:
General SciencePhysics
- ABoth A and R are true and R is the correct explanation of A
- BBoth A and R are true but R is NOT the correct explanation of A
- CA is true but R is false
- DA is false but R is true
Explanation
In the accelerating train's (non-inertial) frame, a pseudo-force of magnitude m·a acts on the coin opposite the train's acceleration, so the coin lands behind the thrower — away from the engine — not ahead of him; the assertion is therefore false. The reason correctly describes this pseudo-force (mass × acceleration of the train), so it is true. A false, R true — option (D).