Help me with this please

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

Which change would make the diagram correct?

Ahole in the ground in the shape of an inverted cone is 14 meters deep and has radius at the top of 11 meters. the cone is filled to the top with sawdust. the density of the sawdust depends upon the depth, x, following the formula ρ ( x ) = 2.5 + 1.2 e − 0.7 x kg/m3. find the total mass of sawdust in the conical hole.