You drive for 30 min for 30 km East and then another 30 min for 40 km North.Your average velocity for the entire trip is
A)40 km/h.
B)50 km/h.
C)60 km/h.
D)70 km/h.
E)80 km/h.

Question

Quizplus · Accepted Answer

The average velocity is the total displacement divided by the total time taken. The displacement is the straight-line distance from the starting point to the ending point, which is the point where the 30 km east and 40 km north paths meet. Using the Pythagorean theorem, we can find that this distance is:

d = sqrt((30 km)^2 + (40 km)^2) ≈ 50 km

The total time taken is 30 minutes (0.5 hours) for the eastward part and another 30 minutes (0.5 hours) for the northward part, for a total of 1 hour. Therefore, the average velocity is:

v = d/t ≈ 50 km/h

Therefore, the best choice is B, with an explanation as given above.

You Drive for 30 Min for 30 Km East and Then