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5. An athlete runs 5.4 laps around a circular track that is 400.0 m

long. If this takes 540 s, what is the average velocity of the athlete?
What is the average speed of the athlete over the complete
distance of the run?

User Gibertoni
by
7.7k points

1 Answer

5 votes

Answer:

Average velocity = 40 m/s

Average speed = 4 m/s

Step-by-step explanation:

We are given;

  • Number of laps covered as 5.4 laps
  • Distance for 1 complete lap is 400.0 m
  • Time taken is 540 seconds

We are required to calculate the average velocity and the average speed of the athlete.

#1. Average velocity of the athlete

  • Velocity is a vector quantity given by dividing displacement with time taken.

In this case,

  • The displacement is 0.4 × 400 m = 160 m
  • This is because for the five complete laps displacement is zero because the athlete will be at the same starting point.
  • Time taken for one lap is 540 s ÷ 5.4 = 100 s
  • Therefore; for 0.4 laps time taken will be 0.4 × 100 = 40 s

Thus;

Velocity = Displacement ÷ time

= 160 m ÷ 40 s

= 40 m/s

The average velocity of the athlete is 40 m/s

#2. Average speed of the athlete

Speed is a scalar quantity calculated by dividing distance by time taken.

In this case;

Total distance is 5.4 × 400 m = 2160 m

time taken is 540 s

Therefore;

Speed = Distance ÷ time

= 2160 m ÷ 540 s

= 4 m/s

Thus, the average speed of the athlete is 4 m/s

User Syd Lambert
by
6.2k points