if a tram suddenly starts, and a stationary person is 'thrown backwards', is his
a) inertia is making him stay where he is while the tram moves toward
b) or is the tram exerting an equal and opposite force on him as he is exerting on the tram, and he is accelerating backwards while the tram accelerates forwards?
In this scenario, when a tram suddenly starts and a stationary person is "thrown backwards," the person experiences a phenomenon known as inertia. Inertia is the tendency of an object to resist changes in its motion.
Option a) Inertia is making him stay where he is while the tram moves forward: This statement is correct. According to Newton's first law of motion, an object at rest will remain at rest unless acted upon by an external force. In this case, the person is at rest in relation to the ground and tends to stay that way due to inertia when the tram begins to move forward. The person's body resists the change in motion, causing the perception of being "thrown backwards."
Option b) The tram exerts an equal and opposite force on him as he exerts on the tram, and he is accelerating backward while the tram accelerates forward: This statement is partially correct. While the person is indeed subject to the force exerted by the moving tram, it is not equal and opposite to the force the person exerts on the tram. According to Newton's third law of motion, for every action, there is an equal and opposite reaction. However, in this case, the person's force on the tram is negligible compared to the force exerted on the person by the tram.
To summarize, the person's backward motion is primarily due to inertia, resisting the change in motion caused by the tram's sudden start. While there is a small force ex