Warm-Up Exercise 37

Due 12:15 pm, Tue 20 Nov 2012

Physics 123, Fall 2012

Reading assignment: 39.1-39.3

The Galilean velocity transformation equation, Eqn 39.2 (8th edition), is simple--much simpler than its name implies. It's also sometimes called the "classical velocity addition" formula. It's "obviously" true. Use it to answer this question: A pickup truck is traveling forward at 5 m/s. A man standing in the back of the truck throws a ball forward at 10 m/s (relative to himself). How fast will someone on the ground measure the ball to be traveling?  What is the faulty  assumption on which the equation relies?

Explain in your own words (in language that your non-physics-major roommates could understand) how the Galilean velocity transformation equation and the 2nd postulate of special relativity are at odds with each another.