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)?

Physics In Motion

1. Watch Segment D (Vectors and Scalars), Segment E (Graphical Resolution of Vectors) and Segment F (Mathematic Resolution of Vectors) at https://www.gpb.org/physics-in-motion (The GPB Physics In Motion video series). Then write answers to the following questions, showing all your calculations.

[a] A child with mass Y kilograms (kg) who is skating eastward in a hockey rink at Y centimeters per second (cm/s) runs into another child, also with mass Y kg, who is skating northward at Z cm/s. The children grab onto each other and keep moving across the ice. Draw a diagram of this interaction, labeling all the relevant objects, quantities, and velocity vectors before and after the collision.

[b] What is the velocity (magnitude and direction) of the two children after they collide? Your answer should be significant to two digits.

[c] Do you think these two children are likely to have been injured in the collision? In a paragraph of at most 50 words, explain using scientific and mathematical reasoning why you think so or not. List any reference sources, such as books or websites, if you used them to help you come to your conclusion.

2. 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?

3. 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.