Choose the word that best completes each sentence. Echinoderms are a group of aquatic invertebrates, but they are only found in
water.

The
of an echinoderm is made of hardened plates, which make the animal feel bumpy.

The body of an echinoderm is arranged like the spokes on a wheel. This is called
symmetry.

are there answer choices to this question? this seems like a question where you have options to choose from.

3.2x10^7

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.

d. platinum would have the greatest temperature increase because it has the lowest specific heat.