Only one of the following is possible for a moving object. which one? the velocity is directed eastward and is decreasing, while the acceleration is also eastward. the velocity is directed northward and is increasing, while the acceleration is zero. the velocity is constant at all times, and the acceleration is not zero. the velocity is zero at one instant, and the acceleration is not zero at that instant. the velocity is directed eastward and is increasing, while the acceleration is directed westward.

The velocity is zero at one instant, and the acceleration is not zero at that instant.

Explanation:

We know that

Where

a is the acceleration of moving object

V is the velocity.

When velocity of object is increasing with time then it means that object is accelerated.

When velocity of object is decreasing  with time then it means that object is de-accelerated.

When velocity is constant it means that acceleration of object is zero.

So at particular position the instant velocity of block is zero but acceleration is not zero at that instant.

answer: the rock sample is a sedimentary rock.

explanation:

it is given that:

mass of rock sample, m = 2.7 g

volume of rock sample,

so, density of rock sample will be

since, the density of rock sample is . hence, the rock sample is a sedimentary rock, whose densities varies between .

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