The first one is: head
Second one is: 10 trillion km
When you talk about Hooke's law, it always have to do something with springs. Hooke's Law, from Robert Hooke, saw a relation between the force applied to the spring and the extension of its length. The equation is: F = kx, where k is the spring constant and x is the displacement of the original and stretched lengths. In other words, x is the length of deformation. Hence, the object must be elastic to come up with a displacement or deformation, in the first place. Then, the Hooke's Law is only applicable to elastic materials.
Explanation:
Michael should put the vase at the bottom of the shelf to reduce the potential energy because the height of the vase to the floor is nearly zero.
Anions: negatively charged atoms
Cations: positively charged atoms (CAT-ions are PAWS-itively charged)
Anode: positively charged electrode that allows electrical current flow (positive end of battery)
Cathode: negatively charged electrode that allows electrical current flow (negative end of batter)
There are longitudinal and transverse. Both types of mechanical waves require a medium, transport energy, and have defined wavelengths, frequencies, and speeds.
Differences are that transverse waves oscillate along a direction perpendicular to the direction of travel (like shaking a rope up and down). Longitudinal waves like oscillations along a spring and sound waves, oscillate back and forth along the direction of travel.