A student has begun training for tryouts for the track team by running two miles through her neighborhood every day. Part of the run is a very steep hill. One day, 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 to 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.