A 200g ball begins falling from a height of 15m. What is your estimate of the object's kinetic energy just before it is dropped? Which is the best answer for KE?

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

The air that we breath is made mostly of which gaseous molecule

Newtons view of arrangement of the universe. don't copy from anywhere.