Question

If a car travels 30 mi. north for one-half hour, 50 mi. east for one hour, and 30 mi. south for 30 min., what is the total displacement of the car? mi

Answer 1

Because north and east are positive directions and south is a negative direction, the answer is 50mi.
30mi north+50mi East-30mi south=50mi.

Answer 2

Answer: 50 miles

Explanation:

The car moves 30 mi to the north in 0.5 hours.

then moves 50 mi to the east in 1 hour

then 30 mi to the south in 0.5 hours.

We want to know the displacement of the car, the displacement is defined as the difference between the initial position and the final position.

I will define the x positive axis as east, and the y-positive axis as the north.

Then, the total displacement in the x-axis is 50 miles.

Now, for the y-axis, the car first moves in 30 miles, and then -30 miles (because goes to south). Then in the y-axis, we do not have any displacement.

Then the total displacement is 50 miles.