Which of the following is true regarding the Earth's mantle?
A
It is made mostly of liquid metal that allows it to flow.
B
Its material moves due to convection currents.
C
It is the densest of all of Earth's layers.

D
It is the hottest of all of Earth's layers.

The energy of a photon was found to be 3.38 × 10–19 j. planck’s constant is 6.63 × 10–34 j • s. which color of light corresponds to this photon?

Asolid cylinder and a cylindrical shell have the same mass, same radius, and turn on frictionless, horizontal axles. the cylindrical shell has light-weight spokes connecting the shell to the axle. a rope is wrapped around each cylinder and tied to blocks of equal masses that are held the same height above the ground. both blocks are released simultaneously. the ropes do not slip. which block hits the ground first? or is it a tie?

The first law of thermodynamics states that heat added to a system is neither created nor destroyed but is as it changes into other forms of energy.