Lesson 3 - Answers to Suggested Problems
After you have had a chance to try the suggested
end-of-chapter conceptual questions, problems and exercises,
you can check your answers against mine below. (Please alert
Jason Harlow jharlow@physics.utoronto.ca if you notice any
errors in the answers.)
Conceptual
Questions
2. Distance traveled equals the magnitude of the
displacement when the object is traveling along a straight
line in the same direction. "Magnitude of
displacement" is a scalar, while "displacement" is a vector,
so these cannot be the same.
4. Speed is always positive. The student actually
described the velocity.
7. Temperature is a scalar quantity. There is no direction
associated with temperature. Some scalars can be
positive or negative.
11. Average speed. The average speed is the same as
the magnitude of the average velocity when the car travels
along a straight line in the same direction for the whole
trip.
Problems and Exercises
6. (a) 52.4 m/s. (b) zero
7. 17 Myr
9. 124.9 km/hr, or 34.69 m/s