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22 votes
22 votes
Juanita ran one mile around her school track in six minutes. What is

her average speed, and what is the magnitude of her average velocity?
10 mph, 0 mph
6 mph, 0 mph
6 mph, 6 mph
10 mph, 10 mph

User Jim Nasby
by
2.3k points

1 Answer

8 votes
8 votes

Answer:

The correct option is a) 10 mph, 0 mph.

Step-by-step explanation:

1. The average speed (S) is a magnitude given by:


S = (D)/(T)

Where:

D: is the total distance = 1 mi

T: is the total time = 6 min


S = (D)/(T) = (1 mi)/(6 min)*(60 min)/(1 h) = 10 mph

Hence, the average speed is 10 mph.

2. The average velocity is a vector:


V = (\Delta d)/(\Delta t) = (d_(f) - d_(i))/(t_(f) - t_(i))

Where:


d_(f): is the final distance


d_(i): is the initial distance


t_(f): is the final time


t_(i): is the initial time

Since Juanita ran one mile around her school track, the final position is the same that the initial position, so the magnitude of the average velocity is zero.

Therefore, the correct option is a) 10 mph, 0 mph.

I hope it helps you!

User Oscarkuo
by
2.8k points