Velma, Inside a Train Moving at 20 M/s, Throws a Rock

question 36

Multiple Choice

Velma, inside a train moving at 20 m/s, throws a rock in the forward direction at 5 m/s. According to her the rock moves at 5 m/s. According to Mort, standing on Earth outside the train, the rock moves at [approximately] 25 m/s. Who is correct?

• A) Mort, because he is standing on Earth.
• B) The Wizard of Oz.
• C) Neither, because there is no universal "best" reference frame.
• D) Velma, because she threw the rock.
• E) Both, relative to their own reference frames.

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Definitions:

Net Price

The final price after all discounts, rebates, and other reductions have been applied, excluding taxes and other fees.

Complement Rates

Rates that together complete or fulfill a whole, often used in the context of probabilities where the complement of an event is 1 minus the probability of the event.

Net Price

The final cost of a product or service once all discounts, rebates, and promotions have been applied.

Complement Method

A mathematical technique used to simplify certain types of calculations, often by subtracting a number from a base value like 10 or 100.