Question

if a stationary bus suddenly speeds up passenger are thrown in the backward direction

Answer 1

This is due to inertia of rest. Person's whole body is in rest and his feet are connected to bus but when bus speeds up, his feet comes in motion while the other whole body tends to be in rest and thus the person will get a backward jer..  ✨✨❤️☺️

Answer 2

this is due to inertia of rest
when the bus is at rest the passengers possesses inertia of rest.
but when the bus starts suddenly the lower body of a person at rest comes in contact with the lower part of bus in motion.
hence inertia of rest changes to inertia of motion

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