A student has begun training for tryouts for lacrosse by running a two mile loop through her neighborhood every evening. Part of the run is a very steep hill. One evening, the student is running down the hill at a very quick pace when she notices a dog lying in the middle of her path. To avoid hitting the dog, she tries to stop but has difficulty. With effort, she is able to stop right before running into the dog. Explain why it was so difficult for the student to stop. In your response, be sure to include: The role of Newton's first law in making it difficult for the student to stop. The correct use of the term inertia. Why some objects in motion have more inertia than others.

It was difficult for the student to stop because of her inertia. According to Newton's first law of motion which states that a body will continue in its state of rest or uniform motion unless there is a force which causes a change in its state of rest or uniform motion.

So, for the girl, she is already in motion before she sees the dog. According to Newton's first law of motion, the natural tendency is for her to continue in that state of motion. But, as she sees the dog, she exerts a force which causes a change in her state of motion, so she stops. This tendency for her continue moving is her inertia and this change in inertia is what was required for her to stop. But according to Newton's first law, her tendency is to continue moving. So, her inertia makes it difficult for her to stop.

b. Why some objects in motion have more inertia than others.

Since inertia is an intrinsic property of an object, some objects in motion have more inertia than others because, they have a larger mass. and mass is a measure of inertia.