A 1kg object/mass/ falls from a height of 10m into a sandbox. What is the speed of the mass before hitting the sandbox If it travels a distance of 20m into the sand before coming
at rest. What is the average force?

An atom that has fewer electrons that protons is called a positive ion.

British cologoinst admisitrion

Despite their crazy structure, human bones are surprisingly good!

Answer;

hot magma rises and pushes up toward the lithosphere, and as it cools it cycles back down toward the core to be heated again.

explanation; convection currents are the circular pathways taken by a fluid that enhances heat transfer by the process known as convection which occurs in fluids.convection currents transfer heat from one place to another by mass motion of a fluid. earth mantle is in a semi-liquid state and behaves like any other fluid, rising up from the bottom of the mantle after becoming hotter and less dense from heat of the earth's core, as the rock loses heat into the earth's crust it becomes cooler and more dense, then sinking back down to the core, then repeating the cycle.