Acar moves in a straight line at 22.0 m/s for 10.0miles, then at 30.0 m/s for another 10.0miles. calculate the car’s average speed in m/s

25.38 m/s

Explanation:

We have a straight line where the car travels a total distance , which is divided into two segments :

(1)

Where

On the other hand, we know speed is defined as:

(2)

Where is the time, which can be isolated from (2):

(3)

Now, for the first segment the car has a speed , using equation (3):

(4)

(5)

(6) This is the time it takes to travel the first segment

For the second segment the car has a speed ,  hence:

(7)

(8)

(9) This is the time it takes to travel the secons segment

Having these values we can calculate the car's average speed :

(10)

(11)

Finally:

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