Question

A person jogs East 50 meters in 20 seconds, then jogged 80 meters in 30 seconds, turned westward, and jogged 40 meters in 40 seconds, and then 190 meters in 40 seconds. What is the average speed and the average velocity of the jogger?

A) Average speed: 3.4 m/s, Average velocity: 0 m/s
B) Average speed: 4.1 m/s, Average velocity: 0 m/s
C) Average speed: 3.4 m/s, Average velocity: 1.2 m/s east
D) Average speed: 4.1 m/s, Average velocity: 1.2 m/s east

Answer 1

The average speed of the jogger is 2.77 m/s, while the average velocity is -0.77 m/s west, indicating that both choices A and B given by the student are incorrect.

Step-by-step explanation:

To find the average speed and average velocity of the jogger, we must consider the total distance jogged and the total time taken, as well as the displacement and direction.

Total distance jogged = 50 m (east) + 80 m (east) + 40 m (west) + 190 m (west) = 360 m
Total time taken = 20 s + 30 s + 40 s + 40 s = 130 s
Average speed = Total distance / Total time = 360 m / 130 s = 2.77 m/s

Since the jogger went 50 m east, 80 m east, 40 m west, and then 190 m west, the displacement is:
Net displacement = (50 + 80) - (40 + 190) = 130 m (east) - 230 m (west) = -100 m (west). Therefore, the displacement is 100 meters to the west.

Average velocity = Displacement / Total time
= -100 m / 130 s = -0.77 m/s (to the west)