Can someone please actually help me on plate tectonics!! The ones labelled have already been known to be right so I need help on the rest.

Aparticle with mass 1.81×10−3 kg and a charge of 1.22×10−8 c has, at a given instant, a velocity v⃗ =(3.00×104m/s)j^. what are the magnitude and direction of the particle’s acceleration produced by a uniform magnetic field b⃗ =(1.63t)i^+(0.980t)j^?

An object has a weight of 500 on earth what is the mass of this object

Identify the theory that can be used to explain each phenomenon. answers diffraction: wave theory interference: wave theory reflection: both particle and wave theories refraction: both particle and wave theories