Question with mean value theorm

[phawksbball24]

The question says that a car begins traveling at 19 mph at 10:00 and continues driving and reaches a speed of 84 mph at 10:30 and you are suposed to find the point at which it equals x mi/h^2

i thought i would use the mean value theorm for this problem but i am not getting the right answer through this, i might be using the wrong values for f(b)-f(a) / b-a i used 84-19 / 30 but i am pretty sure that is incorrect or perhaps i am doing completly the wrong thing, any help would be greatly appreciated

 

[stapel]

I'm afraid I'm not clear on what you mean. Please reply with the exact text of the exercise in question.

Thank you.

Eliz.

 

[skeeter]

you did not calculate the average rate of change of velocity correctly ... the units messed you up.

i might be using the wrong values for f(b)-f(a) / b-a i used 84-19 / 30

speeds are in miles per hour

you used minutes in the denominator

30 minutes = 1/2 hour, correct? ...
your calculation should be (84 - 19)/(1/2) = 130 miles/hr²