Final answer:
The average speed of the car over the entire journey is 11.11 meters per second, which is equivalent to 40 kilometers per hour when converted.
Step-by-step explanation:
To calculate the average speed of the car over the entire journey, we need to find the total distance traveled and the total time taken. The car travels 200 meters in 20 seconds and then 300 meters in 25 seconds.
We add both distances to get the total distance:
200 m + 300 m = 500 m.
Similarly, we sum the times to get the total time:
20 s + 25 s = 45 s.
Now, the average speed (Vavg) is the total distance divided by the total time, so:
Vavg = Total Distance / Total Time
Vavg = 500 m / 45 s = 11.11 m/s.
To convert this speed to kilometers per hour (km/h), we use the conversion factors:
1 m/s = 3.6 km/h,
So:
Vavg in km/h = 11.11 m/s × 3.6 km/h = 40 km/h.