Arock rolls down a steep hill. it's initial velocity is 1 meter per second. by the time it reaches the bottom of the hill 30 seconds later, it's velocity is 7 meters per second. what is the acceleration of the rock?

0.2m/s²

Explanation:

Acceleration is defined as the change in velocity of a body with respect to time. Mathematically,

Acceleration = change in velocity/time

Change in velocity = Final velocity - initial velocity

Acceleration = final velocity - initial velocity/time

Given initial velocity = 1m/s

Final velocity = 7m/s

Time taken = 30seconds

Substituting this values into acceleration formula we will have;

Acceleration = 7-1/30

Acceleration = 6/30

Acceleration = 0.2m/s²

Therefore the acceleration of the rock is 0.2m/s²

the old price per ounce is c/4.

the new price per ounce is c/3.6.

the ratio of the old price to the new one is

(c/4)/(c/3.6) = (c/c)×(3.6/4) = 0.9 . . = 9/10 . . "nine tenths" in either form

this would be about 43%