Which layer is at the center of the earth, and exists as a hot, dense ball of (mostly) iron?

If forces acting on an object are unbalanced, which factors may result fron an unbalanced force? check all that apply

Photoelectrons with a maximum speed of 6.50 x 107 m/s are ejected from a surface in the presence of light with a frequency of 6.75 x 1014hz. if the mass of an electron is 9.10 x 10-31 kg, calculate in joules the maximum kinetic energy of a single electron. 3.84 x 10-15 j 1.92 x 10-15 j 5.92 x 10-23 j 3.07 x 10-16 j

Which accounts for an increase in the temperature of a gas that is kept a constant volume