I need help with all these. Number them pleaseee

1. While descending in an elevator your body (and blood within it) is travelling downwards. If the body stops suddenly the inertia of the blood will try to maintain its motion, so blood will rush from the head downwards towards the feet.

2. When the bottle is pushed downwards the ketchup moves with the bottle. When the bottle is stopped by our hand, the inertia of the ketchup keeps it going and out if the bottle.

3. Before the rest-end collision the body (and head) move with the sand velocity. At the moment of impact the body of a person accelerates forward but the head of the person tried to remain with its initial velocity (because of its inertia) and that means the head appears to move abruptly backwards.

4. While skating, both you and the skateboard move with the same velocity. If the skateboard stops suddenly the person’s inertia would make it continue to move forward with its original velocity.

5. When passenger in a car and the car swerves suddenly to the left, your inertia will want to maintain your velocity. You end up hitting the side of the car as it comes towards you.

2. they have negligible mass.