I am having a hard time can someone help, no fakes please!

What causes the formation of ocean currents?

What is the name of the perceived change in a sound wave’s frequency due to motion between the observer and the sound source?

3. a particle with initial velocity v⃗ 0=(5.85×103m/s)j^ enters a region of uniform electric and magnetic fields. the magnetic field in the region is b⃗ =−(1.35t)k^. you can ignore the weight of the particle. a. calculate the magnitude of the electric field in the region if the particle is to pass through undeflected, for a particle of charge +0.640 nc.