A car drove 17m/s [N] for 10 seconds, and then speeds up to 25m/s [S] for 7.4 seconds. What is the average speed of the car?
To find the average speed of the car, we need to calculate the total distance traveled and divide it by the total time taken.
First, let's calculate the distance traveled in the first part of the journey when the car drove at 17m/s for 10 seconds. Since speed is defined as distance divided by time, we can use the formula:
Distance = Speed × Time
Distance 1 = 17m/s × 10s = 170 meters
Next, let's calculate the distance traveled in the second part of the journey when the car speeds up to 25m/s for 7.4 seconds:
Distance 2 = 25m/s × 7.4s = 185 meters
Now, we can calculate the total distance traveled by adding the distances in the two parts of the journey:
Total distance traveled = Distance 1 + Distance 2 = 170m + 185m = 355 meters
To find the average speed, we can use the formula:
Average Speed = Total Distance ÷ Total Time
Total time = 10s + 7.4s = 17.4 seconds
Average Speed = 355m ÷ 17.4s ≈ 20.40 m/s
Therefore, the average speed of the car is approximately 20.40 m/s.