A car travels north at 30 m/s for one half hour. It then travels south at 40 m/s for 15 minutes. The total distance the car has traveled and its displacement are:
A) 18 km; 18 km S.
B) 36 km; 36 km S.
C) 36 km; 36 km N.
D) 90 km; 18 km N.
E) 90 km; 36 km N.

Question

Quizplus · Accepted Answer

The total distance traveled is the sum of the distances in both directions: north (30 m/s * 1800 s = 54,000 m or 54 km) and south (40 m/s * 900 s = 36,000 m or 36 km), which equals 90 km. The displacement is the difference between the distances north and south, which is 54 km - 36 km = 18 km north.

A Car Travels North at 30 M/s for One Half