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.

How is sound energy produced a. vibrating objects b. objects being heated c. temperature differences d. stationary objects

You are driving directly behind a pickup truck, going at the same speed as the truck. a crate falls from the bed of the truck to the road. (a) will your car hit the crate before the crate hits the road if you neither brake nor swerve? (b) during the fall, is the horizontal speed of the crate more than, less than, or the same as that of the truck?

Four point charges each having charge q are located at the corners of a square having sides of length a. find symbolic expressions for the following. (a) the total electric potential at the center of the square due to the four charges (use any variable or symbol stated above along with the following as necessary: ke.) vtotal= (b) the work required to bring a fifth charge p from infinity to the center of the square (use any variable or symbol stated above along with the following as necessary: w=