Mort, Who Is Standing on the Ground, Throws a Ball

question 54

Multiple Choice

Mort, who is standing on the ground, throws a ball at 20 m/s westward as measured by him. What is the ball's velocity relative to Velma, who is in a train moving eastward past Mort at 70 m/s?

• A) 50 m/s westward
• B) 50 m/s eastward
• C) 90 m/s westward
• D) 70 m/s westward
• E) 90 m/s eastward

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Definitions:

Red Blood Cells

Also known as erythrocytes, these are the cells in the blood responsible for carrying oxygen from the lungs to the rest of the body and returning carbon dioxide back to the lungs.

Oxygen

A chemical element vital for most forms of life on Earth, used in respiration and medical therapies.

Carbon Dioxide

A gas found in the air, exhaled by all animals; the chemical formula is CO2.

Phenylketonuria

A genetic disorder resulting from the body’s failure to oxidize an amino acid, perhaps because of a defective enzyme.