Unit: Mechanics
Year: 1992 Question#: 6
Question: A student walks 1.0 kilometer due east and one kilometer due south. Then she runs 2.0 kilometers due west. The magnitude on the student's resultant displacement is closest to:
(1 ) 0 km
(2 ) 1.4 km
(3 ) 3.4 km
(4 ) 4.0 km
What is this question really asking?
Explanation by: Megan C.
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Answer 1
0 km
INCORRECT
If the students resultant displacement were zero, she would have ended where she be zero. return to top
Answer 2
1.4 km
CORRECT
Using the Pythagorean Theorem, we find that the hypotenuse (also the displacement) is equal to the square root of 2km2 which is approximately 1.4 km.
return to top Answer 3
3.4 km
INCORRECT
As we found in answer 2, the displacement is equal to the square root of 2, which is equal to 1.4, not 3.4. return to top
Answer 4
4.0
INCORRECT
4.0 km is equal to the total distance traveled. Distance does not equal displacement. return to top
What's this question really asking?
Do you know the Pythagorean Theorem, and the difference between distance and displacement? return to top
