What is the vacuole in a plant cell?

What property is a characteristic of a substance that can be observed and does not change the identity of the substance

Which is not an example of how an object gains elastic potential energy by stretching? a. jumping on a pogo stick b. pulling on a rubber band c. jumping on a trampoline

You throw a small rock straight up from the edge of a highway bridge that crosses a river. the rock passes you on its way down, 7.00 s after it was thrown. what is the speed of the rock just before it reaches the water 28.0 m below the point where the rock left your hand? ignore air resistance.