a racing car completes a lap of a 300 meter circular track in 20 seconds. the car's average speed for the lap is most nearly
a)0.0m/s b)10m/s c)15m/s d)20m/s e)31.4m/s
300/20 = _____m/s
To find the average speed of the racing car for the lap, we need to calculate the total distance covered and divide it by the total time taken.
First, let's calculate the circumference of the circular track. The circumference of a circle is given by the formula:
C = 2πr
where C is the circumference, and r is the radius of the circle. In this case, the radius is half of the diameter, which is 300 meters. So the radius, r, is 150 meters.
Now, let's substitute the values into the formula to find the circumference:
C = 2π(150)
C = 300π
Since the car completes one lap, it means it covers the entire circumference of the track, which is 300π meters.
Next, we divide the total distance covered by the total time taken to find the average speed:
Average Speed = Total Distance / Total Time
Total Distance = 300π meters
Total Time = 20 seconds
Now, let's substitute the values into the formula:
Average Speed = (300π) / 20
Average Speed ≈ 15π meters per second
To find the answer, we can approximate π to 3.14:
Average Speed ≈ 15 * 3.14 meters per second
Average Speed ≈ 47.1 meters per second
Therefore, the car's average speed for the lap is most nearly 47.1 m/s.
The closest option to 47.1 m/s is option e) 31.4 m/s.