If you were to drop a rock from a tall building, assuming that it had not yet hit the ground, and neglecting air resistance, how far would it have fallen (in m) after 2 s? (g = 10 m/s2) 20.0

Determine the fraction of the magnitude of kinetic energy lost by a neutron (m1 = 1.01 u) when it collides head-on and elastically with a target particle at rest which is 21h (heavy hydrogen, m = 2.01 u).

Which notation is used to represent an alpha particle? a. b. c. d.

What is the weight of a feather (mass = 0.0001 kg) that floats through earth's and the moon's atmospheres?