Answer:
Step-by-step explanation:
Initially, the plastic bottle lies sideways on the floor of a stationary bus, so the bottle is also in the stationary state.
When the bus starts moving, the bottle will try to maintain its state of rest as described by Newton's first law, due to which the bottle will slide in the backward direction and at the same time there is frictional force acting on the bottle in the forward direction by the bus floor due to which the speed of bottle starts increasing in the direction of the bus as described by Newton's second law.
After some time, the bus, as well as the bottle will move at the same constant speed as there is an application of frictional force.
On the sudden application of the break, the bus will reach the stationary position, but in order to maintain the inertia, the bottle will slide forward on the bus floor due to the inertia of the bottle as described by Newton's first law and at the same time there is frictional force acting on the bottle in the backward direction by the bus floor due to which the speed of bottle starts decreasing as described by Newton's second law.