If a hockey puck of mass Y grams (g) is moving at Z centimeters per second (cm/s), what is the momentum of this puck in units of kilogram meters per second (kg m/s)? If a child with mass Y kilograms (kg) is being accelerated in a car at 0.89 meters per second squared (m/s2), then how much force is being exerted on that child?

Physics in Motion series

4. Watch Segment B (Scientific Notation and Unit Conversions) and Segment C (Significant Figures) of the Physics in Motion series https://www.gpb.org/physics-in-motion and compute and write answers to the following questions.

[a] If a hockey puck of mass Y grams (g) is moving at Z centimeters per second (cm/s), what is the momentum of this puck in units of kilogram meters per second (kg m/s)?

[b] If a child with mass Y kilograms (kg) is being accelerated in a car at 0.89 meters per second squared (m/s2), then how much force is being exerted on that child? You may choose what units to use to express that force; in this instance, your answer is significant to only two digits.

[c] In 20-40 words, explain why you think scientists make such a big deal about significant digits. Why should we not, for example, just write down all the digits on your calculator screen as an answer to a math-based science problem?

5. Create a question about a person experiencing X newtons of force that uses Newton’s Third Law of Motion to answer it. Then answer it. You will be evaluated on both the appropriateness of the question and the correctness of the answer.