A truck travels due east for a distance of 1.9 km, turns around and goes due west for 7.1 km, and finally turns around again and travels 3.3 km due east (a) What is the total distance that the truck travels? km (b) what are the magnitude and direction of the truck's displacement? magnitude direction km Additional Materials Reading Submit Answer Save Progress 16 2.3 WA.011 It the rar's average speed on the first half of the track was 215 km/h,

The total distance travelled by the track is simply equal to the sum of the length of the paths covered by the track in each part of its motion, regardless of the direction.

Here we have:

[tex]d_1 = 1.9 km[/tex]

[tex]d_2 = 7.1 km[/tex]

[tex]d_3 = 3.3 km[/tex]

So the total distance travelled by the track is

[tex]d=d_1 +d_2 +d_3 = 1.9 + 7.1 +3.3 =12.3 km[/tex]

(b) 1.9 km, west

The displacement of the truck is a vector connecting its starting position with its final position in a straight line.

Since all the movements of the track are along the east-west direction (so, they are in line), we can calculate the magnitude of the displacement by simply adding each part of the motion with the proper sign.

Taking the east direction as positive and the west direction as negative, the three displacements are:

[tex]d_1 = +1.9 km[/tex] (east)

[tex]d_2 = -7.1 km[/tex] (west)

[tex]d_3 = +3.3 km[/tex] (east)

Therefore, the total displacement is

[tex]d=+1.9 -7.1+3.3=-1.9 km[/tex] (west)

So, the magnitude of the displacement is 1.9 km, and the direction is west.