An irregularly shaped stone was lowered into a graduated cylinder holding a volume of water equal to 20L. The height of water rose to 30.2mL. If the mass of the stone was 25g what was its density?

2.45 g/mL

Explanation:

(assuming that the original volume was 20 mL and not L)

Since you know the amount of water in the cylinder before and after you placed the rock in, you can subtract them to get the volume of the rock itself. mL.

To get the rock's density, use the equation , where m is mass and v is volume.

c) up

hope this

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.