Question

Lila is a track and field athlete. She must complete four laps around a circular track. The track itself measures 400 meters from start to finish and the race took her 6 minutes to complete. Which best describes her speed and velocity? (There are 60 seconds in 1 minute.)

Answer 1

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

Explanation:

Formulae :$\text{Speed}=\dfrac{\text{Distance}}{\text{Time}}$

$\text{Velocity}=\dfrac{\text{Displacement}}{\text{Time}}$

Given: Length of track start to finish=  400 meters

After completing its 4 laps, total distance covered = 400 × 4 = 1600 meters

Time taken by Lila =   6 minutes

= 6 × 60 seconds      [There are 60 seconds in 1 minute.]

= 360 seconds  

Then, $\text{Speed}=\dfrac{1600}{360}=\dfrac{40}{9}m/s$

$= 4.44\ m/s$

But from start to finish displacement = 0 m   [displacement is the shortest distance between starting point to the finishing point]

So, $\text{Velocity}=\dfrac0{360}=0\ m/s$

Hence, Her speed is 4.4 m/s, and her velocity is 0 m/s.