Answer to Question #144215 in Mechanics | Relativity for Mikkos Joshua Garcia

Question

1. Suppose you are in a bus that is travelling on a straight road and speeding up. If you could stand in the aisle on roller skates, you would start moving backward relative to the bus as the bus gains speed. If instead the bus was slowing to a stop, you would start moving forward down the aisle. Is Newton's law valid? Explain.
2. You are driving a car at a red stoplight. A small stuff toys hangs from your rear-view mirror. As you wait inside the car, the stuff toy is at rest relative to you. Gravity pulls the stuff toy down while the string pulls it up. These two forces are equal, resulting to a zero total force. The stoplight signals "Go" and you step on the gas. The stuff toy swings towards the back of the car. Is Newton's First Law applicable on the stuff toy?

Answer 1

1) Newton's Law is valid in this case, as in the first version, we were moving uniformly relative to the earth at acceleration of the bus according to the law of inertia wanted to stay in the same condition as the second embodiment, when the bus slowed, we continued to move as sought by law 1 Newton's law to remain in the same state.

2) Yes, it is applicable, since the toy was at rest, but after we started to accelerate, according to Newton's law, the toy tended to return to the same state.