Physics Motion Practice Quiz – SOLUTIONS
1) The image below shows the path that the skier travels at the top of the hill.
a) What is the total distance that the skier covers by going from point A to B to C to
D?
The total distance can be broken down into each of the segments: A-B, B-C, and
C-D. The distance that the skier travels from point A to B is 180 m. In the same
way, the skier travels 140 m from point B to C and 100 m from point C to D. The
total distance is determined by adding up the distances for these segments.
A-B = 180 m; B-C = 140 m; C-D = 100 m
Total distance = 180 m + 140 m + 100 m = 420 m
b) What is the skier's total displacement at the end when the skier is at point D?
The skier’s total displacement is the change in position from start (point A) to
finish (point D). The change in position from point A to point D is 140 m to the
left/west
c) If the skier’s total travel time is 20 minutes, what is the skier’s average speed and
the skier’s average velocity?
The formulas for average speed and average velocity are the following: average speed = total distance/total time; average velocity = displacement/total time The total distance was already found in part (a) and the displacement was just determined in part (b). Now that the total travel time has been provided, the speed and velocity values can be calculated. average speed = 420 m/20 min = 21 m/min average velocity = 140 m [to the left]/20 min = 7 m/min [to the left] 2) Xavier goes hiking in the mountains and traveled in the following fashion:
– 3 km, East
– 5 km, North
– 3 km, West
a) Draw the vectors that represent these distances and determine
the resultant/final vector.
Add the vectors
up using the
tail-to-tip method.
The black dotted line represents the
resultant/final displacement vector.
b) How does the distance traveled compare with the magnitude of
the displacement vector?
Xavier traveled a total distance of 11 km (3 km + 5 km + 3 km). The magnitude of
his displacement was only 5 km [to the North] which means that he could have
traveled straight North for 5 km and ended up with the same change in position. The
value for the distance traveled is greater than the magnitude of the displacement.
c) If Xavier’s average velocity was 12 km/hour, how much time passed from the
beginning of his hike to the end of the hike?
The relevant formulas for this question is the following:
average velocity = displacement/total time
The displacement was found in the previous parts and the average velocity has been
provided so that time can now be determined.
12 km/hour [to the North] = 5 km [to the North]/ total time
total time = 5/12 hours = 25 min 3) The path of a soccer ball before it is passed off to a final striker for a goal attempt
is described by the vectors shown below. Add the vectors together and determine
the resultant/final vector. The vectors have been added in two different orders but
the final result is still the same.