Please someone help I'll really appreciate it

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^?

The image shows a pendulum in simple harmonic motion the pendulum starts at a and swing to e

What is the moment of inertia i of this assembly about the axis through which it is pivoted? express the moment of inertia in terms of mr