Question

Lila is a track and field athlete. She has to complete four laps around the track, which is 400 meters. The race took her 6 minutes to complete.

Which best describes her speed and velocity?

A)Her speed is 4.4 m/s, and her velocity is 0 m/s.
B)Her speed is 0 m/s, and her velocity is 2400 m/s.
C)Her speed is 4.4 m/s, and her velocity is 4.4 m/s.

Answer 1

The answer is A.
Speed = distance / time
Speed = (4*400) / (6*60) (6*60 to turn minutes to seconds)
Speed = 1600 / 360
Speed = 4.44

Velocity = displacement / time
since she is running in a circle, she stops where she started making he displacement 0
Velocity = 0 / 6*60
Velocity = 0

Answer 2

Answer: A)Her speed is 4.4 m/s, and her velocity is 0 m/s.

Explanation:

The formula to calculate the speed is given by :-

`\text{Speed}=\frac{\text{Distance}}{\text{Time}}`

Given: The length of the track = 400 meters

Time taken to complete 4 laps = 6 minutes =

The total distance covered in 4 laps =
`4*400=1600\text{ meters}`

Now, her speed is given by :-

`\text{Speed}=(1600)/(6*60)}\approx4.44\text{ m/s}`

Since the starting point and the ending point is same , then the her displacement is zero.

Hence, velocity =0