The distance traveled, in feet, of a ball dropped from a tall building is modeled by the equation d(t) = 16t2 where d equals the distance traveled at time t seconds and t equals the time in seconds. What does the average rate of change of d(t) from t = 2 to t = 5 represent?

Question

oswaldmurphy · Answer

The ball travels an average distance of 112 feet from 2 seconds to 5 seconds.
 The ball falls down with an average speed of 48 feet per second from 2 seconds to 5 seconds.
 The ball falls down with an average speed of 112 feet per second from 2 seconds to 5 seconds.
 The ball travels an average distance of 48 feet from 2 seconds to 5 seconds.

Please explain how to do this!

welshfella · Answer

average speed =  distance interval / time interval

welshfella · Answer

t  goes from 2 to 5 
and you can work out the distances by plugging in t = 2 and t = 5 into  d(t) = 16t^2

welshfella · Answer

in other words  average speed is

16(5)^2 - 16(2)^2
---------------
     5 -  2

oswaldmurphy · Answer

Ok. Thank you!

oswaldmurphy · Answer

Is the answer A?

welshfella · Answer

400 - 64  / 3   = 336 / 3 = 112 feet per second

welshfella · Answer

112 is NOT a distance . 112 is a speed

welshfella · Answer

Not A.

oswaldmurphy · Answer

Oh I didnt notice that :P C.

welshfella · Answer

yes C is the correct option.