racing car accelerates uniformly. changes with following average speeds 20m/s for 2sec ;40m/sec for 2s and 60m/s for 6sec . what is overall average speed of car

calculate distance

20*2 + 40*2 + 60*6 =
calculate time
2+2+6

av speed = distance/time

To find the overall average speed of the car, we need to calculate the total distance covered and the total time taken.

First, let's calculate the distance covered during each interval of acceleration.

For the first interval, the car accelerates at an average speed of 20 m/s for 2 seconds. The distance covered during this interval can be calculated using the formula:

Distance = Average Speed * Time
Distance = 20 m/s * 2 s = 40 meters

For the second interval, the car accelerates at an average speed of 40 m/s for 2 seconds. The distance covered during this interval can be calculated using the same formula:

Distance = Average Speed * Time
Distance = 40 m/s * 2 s = 80 meters

For the third interval, the car accelerates at an average speed of 60 m/s for 6 seconds. Again, we can calculate the distance covered:

Distance = Average Speed * Time
Distance = 60 m/s * 6 s = 360 meters

Now, let's find the total distance covered by the car:

Total Distance = Distance of Interval 1 + Distance of Interval 2 + Distance of Interval 3
Total Distance = 40 meters + 80 meters + 360 meters = 480 meters

Next, we need to calculate the total time taken by the car:

Total Time = Time of Interval 1 + Time of Interval 2 + Time of Interval 3
Total Time = 2 seconds + 2 seconds + 6 seconds = 10 seconds

Finally, we can find the overall average speed of the car using the formula:

Average Speed = Total Distance / Total Time
Average Speed = 480 meters / 10 seconds = 48 m/s

Therefore, the overall average speed of the car is 48 m/s.