An astronaut drops a rock off the edge of a cliff on the moon. The distance d(t), in meters, the rock travels after t seconds can modeled by the function d(t)= .5x^2. What is the average speed, in meters per second, of the rock between 5 and 10 seconds after it was dropped

The average speed is 7.5

Step-by-step explanation:

Speed is a physical quantity that expresses the relationship between the space traveled by an object and the time used for it.

Then, the average speed relates the change in position to the time taken to effect that change:

The change in position is the difference between the final position and the initial position, while the change in time is the difference between the final and initial time.

In this case, the starting and ending positions are calculated by replacing the times in the function of the distance d (t):

d(5)= 0.5*5²= 12.5 m

d(10)= 0.5*10²= 50 m

So:

Replacing in the definition of speed:

and solving you get:

speed= 7.5

The average speed is 7.5

answer: the first one

step-by-step explanation: use a calculator and divide the minutes by the dollars.

687.09 dollars       happy now

step-by-step explanation: 6870

1857 times .63 equals 1169.91 subtract that from 1857 you get 687.09