Lila is a track and field athlete. She must complete four laps around a circular track. The track itself is a 400 meter track and it took her 6 minutes total to complete.

Question

Which best describes her speed and velocity? (There are 60 seconds in 1 minute.)

A. Her speed is 4.4 m/s, and her velocity is 0 m/s.
B. Her speed is 1.1 m/s, and her velocity is 0 m/s.
C. Her speed is 0 m/s, and her velocity is 2400 m/s.
D. Her speed is 4.4 m/s, and her velocity is 4.4 m/s.

Answer 1

The correct answer is A. Her speed is 4.4 m/s, and her velocity is 0 m/s.

Speed is the distance traveled per unit of time. In this case, Lila completes four laps around a 400 meter track in 6 minutes, which is a total distance of 1600 meters (4 laps x 400 meters). Her average speed can be calculated by dividing the total distance by the total time: 1600 meters / 360 seconds (6 minutes x 60 seconds) = 4.4 m/s.

Velocity, on the other hand, is the speed of an object in a given direction. Since Lila completes four laps, her final position is the same as her initial position, which means her displacement is zero. Hence, her velocity is also zero.