Question

Tara's car accelerated from 10 miles per hour to 70 miles per hour in 12 seconds.

What is the approximate rate of change in the miles per hour that Tara's car accelerated?

A)
5 miles per hour per second


B)
8 miles per hour per second


C)
18 miles per hour per second


D)
48 miles per hour per second

Answer 1

Rate of change is very similar to slope.
It is the increase in y's/increase in x's.
It took the car 12 second to increase from 10 mph to 70 mph. This is an increase of 60 mph in 12 seconds.
So the rate of change would be 60 mph/12 sec or 5 mph per sec (A)

Answer 2

acceleration=change in velocity/time
a=(70-10)/12
a=60/12
a=5
So it is A

Hope this helps :)