A wooden raft has a mass of 72 kg. When empty it floats in water (density 1000 kg/m3) with 42% of its volume submerged. What mass of sand can be put on the raft without it sinking

Protons and neutrons are found within the nucleus of an atom

What was the first instrument to ever record an earthquake?

Greg drew a diagram to compare two of the fundamental forces. which labels belong in the areas marked x, y and z? gravitational force electromagnetic force x. attractive y repulsive z: infinite range x: infinite range y attractive z. repulsive x. always attractive y: infinite range z: attractive or repulsive x. attractive or repulsive y infinite range z: always attractive